Ketones methyl ketone syntheses

A general convenient alkyl methyl ketone synthesis, which utilises the /7-keto ester system as an intermediate, involves the acylation of a malonate ester by way of the ethoxymagnesium derivative. Hydrolysis and decarboxylation to the ketone is accomplished by heating in acid solution the synthesis of cyclohexyl methyl ketone is the illustrative example (Expt 5.96). 

Shiraishi, Y., Tsukamoto, D., and Hirai, T. (2008) Highly efficient methyl ketone synthesis by acetone. Organic Letters, 10, 3117-3120... 

Cacchi found a new and simple CO-free methyl ketone synthesis using acetic anhydride. Acetophenone was obtained in 74% yield by the reaction of iodobenzene with acetic anhydride using ligand-free Pd catalyst in the presence of... 

Scheme 3 The Buchner-Curtius-Schlotterbeck reaction (methyl ketone synthesis)...

Acetoxy-l,7-octadiene (40) is converted into l,7-octadien-3-one (124) by hydrolysis and oxidation. The most useful application of this enone 124 is bisannulation to form two fused six-membered ketonesfl 13], The Michael addition of 2-methyl-1,3-cyclopentanedione (125) to 124 and asymmetric aldol condensation using (5)-phenylalanine afford the optically active diketone 126. The terminal alkene is oxidi2ed with PdCl2-CuCl2-02 to give the methyl ketone 127 in 77% yield. Finally, reduction of the double bond and aldol condensation produce the important intermediate 128 of steroid synthesis in optically pure form[114]. 

Methamphetannne is a notorious street drug One synthesis involves reductive amination of benzyl methyl ketone with methylamine What is the structure of methamphetamine ... 

The type of synthesis in which the two-atom fragment supplies C-5 + C-6 is uncommon but useful in preparing pyrimidine- and 5,6,7,8-tetrahydroquinazoline-2,4-diamines. Thus, dicyandiamide (S78) with benzyl methyl ketone (S77) yields 6-methyl-5-phenylpyrimidine-2,4-diamine (S79), or with acetophenone it yields 6-phenylpyrimidine-2,4-diamine (62JOC2708). Likewise, with cyclohexanone it yields the tetrahydroquinazolinediamine (SSO) and by using N- substituted dicyandiamides, 2- and/or 4-alkylamino groups may be introduced (65JOC1837). 

Methyl ketones are important intermediates for the synthesis of methyl alkyl carbinols, annulation reagents, and cyclic compounds. A common synthetic method for the preparation of methyl ketones is the alkylation of acetone derivatives, but the method suffers limitations such as low yields and lack of regioselectivity. Preparation of methyl ketones from olefins and acetylenes using mercury compounds is a better method. For example, hydration of terminal acetylenes using HgSO gives methyl ketones cleanly. Oxymercuration of 1-olefins and subsequent oxidation with chromic oxide is... 

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