Orthoacetic acid, ethyl ester

Organophosphine-carbon tetrachloride, chlbrides from alcohols with, 54, 63 Orthoacetic acid, ethyl ester,... 

It was explained (see p. 528) that two formulae for acetoacetic ester had been proposed, one by Frankland and Duppa and another by Geuther. The formation of acetoacetic ester from acetic ester may be effected either by the action of sodium or sodium ethoxide. Claisen supposed that sodium ethoxide is formed by the action of sodium on traces of alcohol in acetic ester. With ethyl acetate it first forms a derivative of orthoacetic acid, which reacts with ethyl acetate to form the sodium compound of acetoacetic ester ... 

High levels of chirality transfer have been observed in ortho ester Claisen rearrangements. Treatment of (2/ ,3E)-3-penten-2-ol with ethyl orthoacetate gave the ethyl ester of (3/ ,4 )-3-methyl-4-hexenoic acid in 90% optical yield.The... 

Johnson et al. used their newly developed orthoester Claisen reaction to achieve a highly stereoselective total synthesis of aM-trans squalene (5)1 (Scheme 1.20. The diene diol 6 underwent Johnson-Claisen rearrangement when it was heated with ethyl orthoacetate in the presence of propionic acid for 3 h at 138 C. The diene dialdehyde 7, obtained by treatment of the resulting ester with lithium aluminum hydride followed by oxidation with Collins reagent, reacted with 2-propenyllithium to give the tetraene diol 8. The tetraene dialdehyde 9, which... 

By careful selection of the reaction conditions 3-butenols undergo efficient dialkoxycarbonylation to produce y-butyrolactone 2-acetic acid esters under 1 bar of CO (equation 65).Although the roles of the additives are not fully understood, the presence of propylene oxide and ethyl orthoacetate is essential to ensure high selectivity to the double carbonylation product. 

A mixture of ethyl DL-leucinate hydrochloride and ethyl orthoacetate heated 1 hr. at 75-90° ethyl N-acetyl-DL-leucinate. Y 90%. - Similarly Butylamine hydrochloride N-butylformamide. Y 85%. - By this method, N-acyl derivs. of amino acid esters can be obtained directly from easily accessible and stable hydrochlorides. S. V. Rogozhin, Y. A. Davidovidi, and V. V. Korshak, Izvest. 1970, 727 C. A. 73, 15212. 

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