Diacetone alcohol synthesis

One of the most thoroughly investigated aldol condensations is the selfcondensation of acetone. This is an important industrial reaction for the production of diacetone alcohol (DA) (Scheme 11), which is valuable as a chloride-free solvent and an intermediate in the synthesis of industrially important products such as mesityl oxide (MO), isophorone, methyl isobutyl ketone, and 3,5-xylenol. The reaction is exothermic, with the yield of DA decreasing with increasing reaction temperature it is usually performed with NaOH or KOH as a basic catalyst 118). 

A similar method was developed for the synthesis of di- and trisubstituted tetrazolium salts through the quaterni-zation of 1- and 2-monosubstituted tetrazoles, including functionally substituted compounds, with diacetone alcohol <1999CHE1078> and tert-butanol <2001CHE949> in perchloric acid, and 2,5-dimethyl-2,5-hexandiol in sulfuric and perchloric acids <2000CHE326>. In the latter study <2000CHE326>, this method was used for a selective synthesis of binuclear N-substituted tetrazoles and tetrazolium salts. 

Acetone is used as a solvent for cellulose acetate, nitrocellulose and acetylene as a raw material for the chemical synthesis of such products as ketones, acetic anhydride, methyl methacrylate, bisphenol-A, diacetone alcohol, methyl isobutyl ketone, isophorone, etc. 

The aldol condensation is a class of reactions widely used in organic synthesis for the production of various oxygenated compounds (Figme 1). The reactions may be conducted in the liquid or vapor phase with a variety of catalysts. We are interested in the application of CD to the aldol condensation of acetone (Ac) to examine the factors that determine the yield and selectivity in reactions involving a number of consecutive steps. Under ambient reaction conditions, diacetone alcohol (DAA) is readily formed. At higher temperatures DAA readily undergoes dehydration to mesityl oxide (MO) [2],... 

Acetone addition and condensation have been extensively studied [175, 188. 253-255] Figure 7). Acetone can undergo addition to form diacetone alcohol which can be dehydrated to produce mesityl oxyde. used in the synthesis of methyl isobuihyl ketone (MIBK). Moreover, as already described in section 3. the puKluci distribution for acetone condensation is a useful way to reveal information about the surface chemistry of the catalyst [45. 235]. 

Garcia Ra.so, A Sinisterra, JV Marinas, JM. A new barium hydroxide catalyst for synthesis of diacetone alcohol. Reaction Kinetics and Catalysis Letters. 1981 18, 33-37. 

HMB is used as a nutritional supplement for human beings and also as an animal feed additive, and acts by suppressing protein breakdown. It is manufactured by Metabolic Technologies Inc. (Ames, Iowa). The reactions comprising the synthesis of HMB are the main reaction involving the decomposition of diacetone alcohol, known as the halofoim reaction, accompanied by several side reactions. 

The liquid-phase condensation of acetone is an important industrial process for the synthesis of a series of commodity chemicals like diacetone alcohol (DAA), mesityl oxide (MO) and methyl isobutyl ketone (MIBK) (/). MIBK is extensively... 

Schneider and Hansch used Zr(0 Bu) to catalyze the synthesis of acetone aldol adducts, 103, of aromatic aldehydes and diacetone alcohol, 102, (reaction 7.19) in moderate yields [69,70]. Moreover, they used it for rapid catalysis of Tishchenko reduction (reaction 7.20) of the P-hydroxyketones, 102, instantaneously get ahead the aldol reaction with some aliphatic aldehydes to yield the 1,3-awfi-diol monoesters, 104. 

Replacement of diacetone alcohol (or mesityl oxide) by the aliphatic a-hydroxy-ketones L186 or L187 (Eq. 2.117) does not permit the synthesis of 14-membered... 

The most important source of acetone is the Hock process for phenol production. In this process acetone is obtained as stoichiometric coupling product. If acetone needs to be produced deliberately, it can be obtained by oxidative dehydrogenation or dehydrogenation of isopropanol. Oxidative dehydrogenation proceeds at 400-600 °C at silver or copper contacts, direct dehydrogenation is carried out at 300-400 °C using zinc contacts. Alternatively, acetone can also be obtained by a Wacker-Hoechst oxidation of propylene. Acetone is used industrially as solvent. Moreover, the aldol condensate products of acetone (diacetone alcohol) are used as solvents. Acetone is also converted in an add catalyzed reaction with two moles of phenol for the synthesis of bisphenol A. Bisphenol A is an important feedstock for the production of epoxy resins and polycarbonates. 

There are two main synthesis routes in commerce to produce MIBK. One starts with acetone and involves intermediates of diacetone alcohol and mesityl oxide. The second synthesis route uses 2-propanol, involving a mixed ketone process with coproducts including diisobutyl ketone (DIBK) and acetone. 

Nickel oxide anodes are another example for a relatively simple oxide electrocatalyst used rather widely in the oxidation of organic substances (alcohols, amines, etc.) in alkaline solutions at relatively low anodic potentials (about +0.6 V RHE). These processes, which occur at an oxidized nickel surface, are rather highly selective. As an example, we mention the industrial oxidation of diacetone-L-sorbose to the corresponding acid in vitamin C synthesis. This reaction occurs at nickel oxide electrodes with chemical yields close to 100%. 

Alcohols can be converted electrochemically into the corresponding carboxylic acids in very good yields if Ni oxide anodes are used in alkaline electrolytes. This reaction was studied intensively in industry for the electrochemical oxidation of diacetone-L-sorbose to diacetone-2-ketogulonic acid (intermediates of the vitamin C synthesis). On the basis of Sowjet work 282 284) (initially Pt anodes and NaBr—NaCl—NiCl2— NaOH electrolytes subsequently Ni oxide anodes), Roche and Merck studied the synthesis on the laboratory and pilot scale. In cooperation with the ETH Zurich 285-286 a special cell 287 288) was developed for this reaction. 

The diacetone glucose 767 was the best reagent and has been used in the synthesis of the allenic alcohol 769 (92% de) which, after protection of the hydroxy group and final hydrolysis, afforded the unsaturated ketol derivative 770 (Scheme 199). This compound 770 is a key intermediate in the total synthesis of the cytotoxic styryl lactone (-t-)-goniodiol1051,1089. 

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