A Chemical Perspective

Describing the chemistry of the world we live in, one post at a time.

[chemicalcuriosities]

Nomenclature Corner: Agranoff's Turtle

Of the nine different stereoisomers of 1,2,3,4,5,6-cyclohexanehexol, myo-inositol is arguably the most biologically relevant. myo-Inositol, in the form of phosphatidylinositol 4,5-bisphosphate (marked as A in the second image), serves critical functions in cell signalling: when hydrolyzed by phospholipase C, the secondary messenger inositol 1,4,5-trisphosphate (often abbreviated as IP3) is released. IP3 can then induce opening of calcium channels in the endoplasmic reticulum, among many other functions. In addition to this trisphosphate, myo-inositol can also be found in a wide variety of phosphorylated states in biological systems.

63 different phosphomonoesters of myo-inositol are possible, which produces a large potential for confusion when trying to precisely specify the phosphorylation states. To help mitigate this confusion, Dr. Bernard Agranoff (Professor Emeritus, University of Michigan) developed a mnemonic based on the superficial similarity of myo-inositol to a turtle when drawn in its chair form.

In this mnemonic (commonly referred to as "Agranoff's turtle"), the head, four flippers, and tail of a turtle all represent a hydroxyl group. The axial hydroxyl is referred to as the turtle's head, while the flippers and tail represent the five equatorial hydroxyls. Numbering begins with the right flipper and proceeds counterclockwise, as is conventional for a D-based numbering system. (The L-based numbering system starts at the left flipper and proceeds clockwise instead.)

Using Agranoff's turtle to guide the numbering of myo-inositol has helped reduce confusion and misunderstandings when discussing its various phosphorylated derivatives. In fact, this mnemonic has been so successful, it has even been recommended by the International Union of Biochemistry Nomenclature Committee!

References: (1): Agranoff, B. W. J. Biol. Chem. 2009, 284(32), 21121-21126. (2): Biochem. J. 1988, 258, 1-2. (Full text)

[chemicalcuriosities]

Everyday Phenomena: The Maillard Reaction

At first glance, steak, French fries, bread, milk caramel, and soy sauce don’t have very many similarities. However, the preparation of these foods all have one thing in common: browning that occurs via the Maillard (my-YAR) reaction.

The Maillard reaction was first discovered in 1912 by Louis-Camille Maillard, and refers to a long chain of reactions that ultimately leads to browning of food. This chain typically begins with the condensation of an amine (often the amino acid lysine) with a reducing sugar (containing an aldehyde); one example of this Amadori rearrangement is shown above with lysine and glucose.

This Amadori product can react in a variety of different ways, including dehydration and deamination to produce a diverse array of molecules that give browned food a distinctive flavor; a few of these compounds are shown above. At the end of the sequence of reactions that occur during browning is a class of polymeric compounds known as melanoidins, which lend a brown color to the food.

Below about 140°C (280°F), the Maillard reaction does not proceed at an appreciable rate, although alkaline conditions (such as the lye used to make pretzels) can accelerate the process. Without this reaction, many foods we enjoy now wouldn’t be nearly as tasty!

Further Reading: Hodge, J. E., J. Agric. Food Chem. 1953, 1 (15), 928-943 (Full text)

[chemicalcuriosities]

Here are the answers to the trivia questions posted last week!

Ooh, Pretty Colors! Solutions of potassium permanganate are strongly colored, due to intense ligand-metal charge transfer excitations from the oxo lone pairs to the empty metal d orbitals. Depending on the concentration, the solutions can range from light pink to almost black.

The Chemist’s Toolbelt AXE designations are used to describe the geometry around simple covalent molecules, and especially for hypervalent molecules. The A refers to the central atom (always implied as 1), the X refers to the number of atoms bonded, and the E refers to the number of lone pairs.

What’s In a Name? 磷 is the Chinese character for phosphorus. One of the allotropes (white phosphorus) glows on exposure to oxygen. Other allotropes include red and black phosphorus.

I Guess Other Sciences Also Exist During Philae’s landing, misfired harpoons and thrusters led to poor positioning of the probe in the shadow of a cliff. The lack of sunlight led to Philae being unable to generate power through its solar cells, and no communication between it and Rosetta has occurred since July 2015.

“What am I, Dr. Chemist?” An m/z of 91 is often characteristic of the tropylium cation, formed by rearrangement of a tolyl cation. This rearrangement is favorable in the gas phase due to tropylium being an aromatic species.

Which One’s The Büchner Funnel? Soxhlet extractors are useful in extracting a sparingly soluble material out of a solid. The design of the funnel allows for repeated washes with clean and hot solvemt

[chemicalcuriosities]

The Cutting Edge: Confirmation of Elements 113, 115, 117, and 118

On December 30, 2015, IUPAC officially verified the existence of the transactinide elements ununtrium, ununpentium, ununseptium, and ununoctium (Z = 113, 115, 117, 118). Confirmation of the discoveries of these elements completes period 7 of the periodic table; the most recent official confirmations were of flerovium and livermorium (Z = 114, 116) in 2012.

Credit for the discovery of ununtrium (Uut, Z = 113) has been given to the Superheavy Element Production Team at RIKEN (Japan), headed by Kosuke Morita (森田 浩介). This marks the first time that a Japanese team has been credited with the discovery of a new element. Their first results were published in 2004; an earlier report by a joint Russian-American team was not deemed conclusive enough to be considered a true “discovery”.

The discovery of elements ununpentium (Uup, Z = 115) and ununseptium (Uus, Z = 117) has been credited to a three-way collaboration between scientists at the Joint Institute for Nuclear Research (Dubna, Moscow Oblast, Russia), Lawrence Livermore National Laboratory (Livermore, California, USA), and Oak Ridge National Laboratory (Oak Ridge, Tennessee, USA). In addition, JINR and Livermore National Lab scientists are also credited with discovering ununoctium (Uuo, Z = 118). Synthesis of the element occurred at the Flerov Laboratory of Nuclear Reactions, led by Yuri Tsolakovich Oganessian (Юрий Цолакович Оганесян).

As per the official guidelines outlined by the IUPAC, the discoverers of these elements now have the right to choose a permanent name and two-letter chemical symbol for that element. RIKEN has considered a variety of names for element 113, including japonium (Jp) and rikenium (Rk); names for 115, 117, and 118 have yet to be suggested, although moscovium has been proposed in the past.

References: (1) IUPAC Press Release (2) Morita et al. J. Phys. Soc. Jpn. 2004, 73, 2593-2596. (3) Oganessian et al. Phys. Rev. C 2004, 69, 021601. (4) Oganessian et al. Phys. Rev. Lett. 2010, 104, 142502. (5) Oganessian et al. Phys. Rev. C 2006, 74, 044602.

[chemicalcuriosities]

Around the middle of spring quarter last year, the chemistry club at the University of Washington (which one of your friendly admins of this blog, @cyclopentadiene, was a proud officer of) held a Jeopardy-like trivia night. These are just some of the questions we came up with! 

These questions were designed so that even inexperienced underclassmen would be able to answer some of the questions, whereas the more advanced students and professors may have forgotten the details as taught in gen chem. Answers to these questions will be posted in the future; until then, anybody up for giving a shot at some of these?

[chemicalcuriosities]

Everyday Phenomena: Leaded Gasoline

The internal combustion engines of gasoline-burning vehicles rely on the Otto thermodynamic cycle, where work is derived from the combustion of a compressed fuel-air mixture by a spark in a controlled manner. One major problem with this engine type is known as knocking, which occurs when the fuel-air mixture does not completely combust, leaving pockets of unburned fuel. These pockets of fuel can detonate violently, potentially damaging the engine and causing a characteristic metallic pinging noise.

At the time, solutions to this problem included mixing in ethanol or benzene to the gasoline, and were relatively effective. However, these needed to be added in a large percentage to have an effect. In 1922, Charles Kettering and Thomas Midgley (General Motors) discovered that the organometallic compound tetraethyllead, even when diluted 1000:1, was remarkably effective at supressing engine knocking. Because of its effectiveness, and despite its high toxicity, tetraethyllead was added to nearly all gasoline ("leaded" gasoline). As time passed, the deleterious effects that burning leaded gasoline had on the environment were exposed and efforts were made to phase the additive out.

Reference: Ball, G. E.; Darwish, T. A.; Geftakis, S.; George, M. W.; Lawes, D. J.; Portius, P.; Rourke, J. P., Proc. Natl. Acad. Sci. 2005, 102 (6), 1853-1858 (Full text)

[chemicalcuriosities]

Chemicals of The Day: Sabinene and Zingiberene

In honor of Thanksgiving and all of the pies you will be consuming, I want to shed some light of the molecules that give, nutmeg and ginger, their flavors. Sabinene occurs in plants and it is a bicyclic monoterpene (terpene chemical class) and this is the flavoring for nutmeg. Sabinene occurs as  (+)- and (-)- enantiomers. Zingiberene is obtained from the root of the Chinese plant Zingiber officinale and it is a monocylic sesquiterpene (also from the terpene chemical class). Zingiberene gives ginger its flavoring.

(Source)

[chemicalcuriosities]

Chemicals of the Day: Putrescine and Cadaverine

Happy Halloween! Amine have a foul smell as it, but what are the smells found in decaying animals? Putrescine (butane-1,4-diamine) and cadaverine (pentane-1,5-diamine) are compounds that result in the decomposition of amino acids. Putrescine results from the decarboxylation of ornithine and arginine while cadaverine results from the decarboxylation of lysine. Both compounds were isolated in 1885 by L. Briege and O. Bocklisch.

(Sources 1 & 2)

[chemicalcuriosities]

Nobel Prize in Chemistry 2015, Part 1: Tomas Lindahl and Base Excision Repair

On October 7th, the Nobel Committee announced its decision to award this year’s Nobel Prize in Chemistry to three biochemists, Tomas Lindahl, Paul Modrich, and Aziz Sancar, for their contributions to our understanding of how damaged DNA is repaired. Today, we’ll be looking more closely at Tomas Lindahl (Francis Crick Institute) and his discovery of base excision repair.

Tomas Lindahl was born in Kungsholmen, Stockholm, Sweden in 1938. He earned his Ph.D from the Karolinska Institutet in 1967, and later his MD in 1970. Lindahl’s early work showed that DNA was prone to hydrolysis under cellular conditions, and coined the term “DNA decay” to describe its inherent instability. His research has led to the discovery of many enzymes involved in the repair of damaged DNA; one of the most notable of these is the discovery of base excision repair and the enzyme uracil-DNA glycosylase.

One mode of DNA decay is the spontaneous deamination of cytosine to produce uracil, as shown below.

This poses a problem for the fidelity of DNA replication—uracil is unable to base pair with guanine, and will pair with adenine instead during replication, causing a mutation. Lindahl reasoned that in order to prevent mutations from deamination events, an enzyme to detect and remove uracil from DNA must be present. In 1974, he discovered an enzyme, uracil-DNA glycosylase, that hydrolyzes off the uracil and leaves behind an abasic site. Lindahl later determined the other enzymes required to repair this abasic site, and in 1994 was able to reconstitute the entire repair pathway using purified enzymes from E. coli.

Uracil-DNA glycosylase recognizes deamination events by scanning the DNA for any uracil present. Once uracil is detected, the enzyme binds to the DNA double helix in a way that forces the uracil to rotate out from the center (a mechanism known as “base flipping”), then catalyzes hydrolysis of the glycosidic bond. The protein structure above (PDB 4SKN) shows the enzyme-DNA complex following hydrolysis, with free base uracil bound and the abasic site still flipped out of the helix.

References: (1) https://en.wikipedia.org/wiki/Tomas_Lindahl (2) http://www.nobelprize.org/nobel_prizes/chemistry/laureates/2015/ (3) The Nobel Prize in Chemistry 2015 - Popular Information / Advanced Information (4) Lindahl, T. Proc. Natl. Acad. Sci. U.S.A. 1974, 71 (9), 3649-3653. (5) Slupphaug, G.; Mol, C. D.; Kavli, B.; Arvai, A. S.; Krokan, H. E.; Tainer, J. A. Nature 1996, 384, 87-92.

[chemicalcuriosities]

Nobel Prize in Medicine 2015, Part 2: William Campbell, Satoshi Ōmura, and the Avermectins

Yesterday, we discussed one half of the 2015 Nobel Prize in Physiology/Medicine, awarded to Tu Youyou for the discovery and isolation of the antimalarial drug artemisinin. Today we’ll be talking about the other half of the Nobel Prize, awarded jointly to William C. Campbell (Drew University) and Satoshi Ōmura (Kitasato University) for their roles in the discovery and development of the avermectins, a class of antiparasitic drugs.

William Campbell was born in Ramelton, County Donegal, Ireland in 1930, earned a degree in zoology from Trinity College, and obtained a Ph.D from the University of Wisconsin. Satoshi Ōmura (大村 智) was born in Nirasaki, Yamanashi, Japan, in 1935. He received his MS from the Tokyo University of Science, a Ph.D in chemistry from the Tokyo University of Science, and a Ph.D in pharmaceutical sciences from the University of Tokyo.

The discovery of the avermectins was made possible through a partnership between the Kitasato Institute in Japan and the Merck, Sharpe and Dohme (MSD) labs in the US. In 1974, a research group led by Ōmura isolated Streptomyces avermectinius from a golf course near Itō, Shizuoka. This organism was discovered to produce 8 different compounds with high antiparasitic activity; this family of molecules was named the avermectins. Isolated cultures of S. avermectinius were sent to the MSD labs, where a team led by Campbell found that hydrogenation of one of the double bonds (top right in the structures above) improved antiparasitic activity while also reducing toxicity; this new family of compounds was termed ivermectin.

Ivermectin has been extremely effective in the treatment of onchocerciasis (river blindness) caused by Onchocerca volvulus. This parasitic worm is found in the tropical regions of South America and Africa, and can cause blindness if they migrate to the eye. Following the development of ivermectin, river blindness has been completely eliminated in Columbia, Ecuador, and Mexico; is very close to being eliminated in Brazil, Venezuela, and Yemen; and has been extremely effective in treating cases in African countries. This was made possible by MSD, which pledged to provide ivermectin free of charge to treat river blindness where it is necessary.

The primary mode of toxicity of ivermectin and the avermectin family is thought to be inhibition of glutamate-gated chloride ion channels found in parasitic nerve and muscle cells (but not in mammalian cells). Binding of ivermectin to these ion channels causes neuronal hyperpolarization, leading to paralysis and death of the parasite.

References: (1) https://en.wikipedia.org/wiki/William_C._Campbell_(scientist) (2) https://en.wikipedia.org/wiki/Satoshi_%C5%8Cmura (3) http://www.nobelprize.org/nobel_prizes/medicine/laureates/2015/ (4) Burg, R. W. et al. Antimicrob. Agents Chemother. 1979, 15 (3), 361-367. (5) Ōmura, S.; Crump, A. Nature Rev. Microbiol. 2004, 2, 984-989.

[chemicalcuriosities]

Nobel Prize in Medicine 2015, Part 1: Tu Youyou and the Discovery of Artemisinin

Nobel Prize season has began, and with that will be a series of posts detailing the chemistry-related prizes that are awarded! Today’s post will be about one half of the Physiology/Medicine prize, awarded to Chinese pharmacologist Tu Youyou for the discovery of the antimalarial drug artemisinin. This is the first natural science Nobel Prize awarded to a native mainland Chinese scientist. (Other awards have been given to scientists of Chinese descent that did their work in other countries.)

Tu Youyou (屠呦呦) was born in Ningbo, Zhejiang, China, in 1930 and graduated from the Department of Pharmaceutical Sciences at Peking University Medical School in 1955, and worked as a researcher at the China Academy of Chinese Medical Sciences afterwards. She participated in a secret government research program, Project 523, that aimed to discover new antimalarial drugs in an effort to aid North Vietnam in the Vietnam War.

The discovery process was guided by traditional Chinese herbal remedies found in ancient medical texts. One particularly effective remedy was found in "The Handbook of Precriptions for Emergency Treatments" (肘後救卒方), a medical text written in the 4th century: “take one bunch of qinghao [Artemisia annua], soak in two sheng [~400 mL] of water, wring it out to obtain the juice, and ingest it in its entirety.” In 1971, Tu was able to extract the active compound from the herb, artemisinin (also known as qinghaosu, 青蒿素, after the Chinese name for the herb). Tu and her colleagues later determined the chemical structure in 1979, and published their findings anonymously.

Artemisinin and its related derivatives are one of the most effective remedies for malaria. The structure of artemisinin includes an unusual peroxo bridge that is crucial to its antiparasitic activity. Upon ingestion, the ester carbonyl is hydrogenated to form dihydroartemisinin, which is the biologically active metabolite. The mechanism through which dihydroartemisinin kills parasites is unknown, but likely involves radical formation from the peroxo bridge, causing oxidative damage to the parasite.

References: (1) https://en.wikipedia.org/wiki/Tu_Youyou (2) http://www.nobelprize.org/nobel_prizes/medicine/laureates/2015/ (3) Miller, L. H; Su, X. Cell. 2011, 146 (6), 855-858. (4) Cumming, J. N.; Ploypradith, P.; Posner, G. H. Adv. Pharmacol. 1996, 37, 253-297

[chemicalcuriosities]

This poster, produced by the KVA/Royal Swedish Academy of Sciences, describes the research on super-resolved fluorescence microscopy performed by Eric Betzig (Janelia Research Campus), Stefan Hell (Max Planck Institute for Biophysical Chemistry), and William Moerner (Stanford) that earned the 2014 Nobel Prize in Chemistry.

You can order a copy of this poster for yourself from the KVA website free of charge!

[chemicalcuriosities]

To whoever had to find that out the hard way, I’m sorry.

[chemicalcuriosities]

Cool Chemistry: Xenon-Metal Bonds

When the elements of Group 18 were first discovered, many scientists believed that since their valence electron shells were already filled, they would be unable to form compounds. With the discovery of xenon hexafluoroplatinate in 1962, this was shown to be false, leading to a name change from "inert gases" to "noble gases". In the 53 years since then, a huge array of new noble gas compounds have been synthesized. These compounds range from simple binary compounds with fluorine (XeF4, KrF2) to more complex molecules with different elements (Ba2XeO6, (C6F5)2Xe).

One of the stranger noble gas compounds is the one shown above: Re(iPrCp)(CO)(PF3)(Xe), discovered by Dr. Jon Rourke (University of Warwick). In this complex, xenon forms a bond with the rhenium metal center by behaving as a 2-electron neutral ligand. This species (complex 3) is formed by irradiating a solution of Re(iPrCp)(CO)2(PF3) in liquid xenon (170 K) with UV light. Synthesis at room temperature is also possible, utilizing supercritical xenon as a solvent at pressures of nearly 60 bar.

The synthesis of complex 3 was performed in a modified NMR apparatus allowing for continuous UV irradiation. 19F NMR spectra taken following irradiation showed three distinct doublets: the leftmost doublet corresponds to the starting material, the central doublet comes from complex 3, and the rightmost doublet comes from free PF3 ligand. Free phosphine ligand indicates the possibility of forming a dicarbonyl species (complex 2), which is otherwise not easily observable via NMR. Additional evidence of the presence of both of these rhenium xenon complexes is provided by FT-IR spectroscopy, performed in a special low-temperature high-pressure spectrometer.

Xenon is naturally present as ten stable isotopes, two of which (129Xe and 131Xe) are spin active. Of these two isotopes, 129Xe is particularly useful in NMR spectroscopy due to its nuclear spin of 1/2. By using labeled xenon gas in the synthesis, spin-spin coupling to fluorine and phosphorus was measured: 3JFXe = 5.1 Hz, 2JPXe = 41.8 Hz. A 129Xe NMR spectrum of complex 3 was also recorded, with the xenon signal appearing at -6179 ppm (reference: liquid Xe, -5135 ppm). HSQC and HMQC, two similar 2D NMR techniques, were used to correlate the peaks of the different nuclei as further evidence for the existence of complex 3.

Reference: Ball, G. E.; Darwish, T. A.; Geftakis, S.; George, M. W.; Lawes, D. J.; Portius, P.; Rourke, J. P., Proc. Natl. Acad. Sci. 2005, 102 (6), 1853-1858 (Full text)

[chemicalcuriosities]

On this day in history: August 16th

Death of Robert Bunsen, 1899

Robert Bunsen was a German chemist, most famously known for his invention that takes his name, the bunsen burner.

Bunsen himself used his invention’s hot, clean flame to study the flame colour produced by burning elements, thus becoming the first person to study emission spectra.

Later, he and his colleague Gustav Kirchhoff used glass prisms to separate the light emitted from the burning samples, creating the scientific field of spectroscopy. Using this technique he would go on to identify the emission spectra of lithium, sodium and potassium, and discover the element caesium. Caesium gets it’s name from the blue line that caesium created in the emission spectra, being derived from the Latin for “deep blue”.

Further reading

http://www.rsc.org/learn-chemistry/collections/chemistry-calendar

http://www.theguardian.com/science/blog/2011/mar/31/robert-bunsen-burner-inventor-chemist

Robert Wilhelm Bunsen. 2015. Encyclopædia Britannica Online. Retrieved 16 August, 2015, from http://www.britannica.com/biography/Robert-Wilhelm-Bunsen

[chemicalcuriosities]

Biochemistry: Sanger’s Reagent

1-Fluoro-2,4-dinitrobenzene (DNFB), also known as Sanger’s Reagent, is most notably known for its use in determining the N-terminal amino acid in polypeptide chains. Frederick Sanger, who gives his name to the molecule, used DNFB to estimate the chain length of insulin. His early experiments found insulin to be made up of four chains that are cross linked by disulfide bonds, and he found the molecule’s length to be much shorter than pre-existing estimates. Later, with a combination of DNFB and some other techniques, he created the complete sequence of insulin, which was found to consist of only two chains.

It was for this work that Sanger was, in 1958, awarded the first of his Nobel Prizes “for his work on the structure of proteins, especially that of insulin”. Sanger is the only person to ever be awarded two Nobel Sciences in Chemistry, the other being awarded in 1980 to himself and his colleague Walter Gilbert “ for their contributions concerning the determination of base sequences in nucleic acids ”.

Further reading: https://en.wikipedia.org/wiki/Frederick_Sanger http://www.nobelprize.org/nobel_prizes/chemistry/ Sanger, F. The  free amino groups of insulin. Biochem. J. 1945, 39(5), 507–515.

[chemicalcuriosities]

Industrial Chemistry: Acetone and Phenol via the Cumene Process

Acetone is one of the most ubiquitous chemicals in any experimental lab; its excellent solubility properties makes it the go-to wash solvent for glassware, and for this reason, acetone is consumed at a very high rate in many labs. But where does all this acetone come from?

Industrially, acetone is produced alongside phenol from benzene and propylene in the cumene process, discovered independently by Hock and Lang (1944) and Ūdris and Sergeyev (1942). Both phenol and acetone can be converted to the monomers of a wide variety of plastics (including polycarbonates, nylon, and epoxide resins), making demand for these two chemicals very high. 

The cumene process is by far the dominant route to both acetone and phenol, producing 95% of the world’s demand for both chemicals. 6 million (metric) tons of acetone and 7.3 million (metric) tons of phenol are produced annually by this process. The cumene process takes place in three main steps: (1) alkylation of benzene to cumene (isopropylbenzene), (2) air oxidation of cumene to cumene hydroperoxide, and (3) acidic cleavage of the hydroperoxide to products.

Step 1: Alkylation of Benzene

In the first step of the cumene process, cumene is synthesized from benzene and propylene by a Friedel-Crafts alkylation. AlCl3/HCl was used as the acid catalyst in the past, but fell out of use due to its corrosive behavior towards the reaction vessel. Modern systems often employ less corrosive solid acids like zeolites to catalyze the reaction. High pressures are used to drive the reaction forward.

Step 2: Oxidation of Cumene

In the second step, cumene is oxidized to cumene hydroperoxide by molecular oxygen via a radical chain mechanism. Initiation of the reaction is done by molecular oxygen, which abstracts a hydrogen radical from the benzylic position of cumene. Prior to moving to the final step of the process, the hydroperoxide is concentrated via distillation. The temperature must be carefully controlled; cumene hydroperoxide undergoes an exothermic decomposition above ~120°C, and could potentially lead to thermal runaway.

Step 3: Acidic Cleavage of Cumeme Hydroperoxide

The final step of the cumene process is the acid-catalyzed cleavage of cumene hydroperoxide to give the final products, acetone and phenol. This cleavage is also known as the Hock fragmentation, and proceeds via a mechanism that is reminiscent of the Baeyer-Villager oxidation. Due to its higher migratory aptitude, the phenyl group preferentially migrates in the rearrangement step. The acid catalyst (most often sulfuric acid) is only required in concentrations as small as 1 mM to allow the reaction to run.

Other methods exist to synthesize acetone (thermolysis of acetate salts, dehydrogenation of isopropanol) and phenol (hydrolysis of chlorobenzene, oxidation of toluene). However, the cumene process dominates in industry due to its high efficiency and well-optimized reaction conditions.

Source: Weber, M.; Weber, M.; Kleine-Boymann, M. Ullmann’s Encyclopedia of Industrial Chemistry; Wiley-VCH, 2013. [Acetone] [Phenol]