Highly Efficient Syntheses of Alkyl 3,3-Dialkoxypropanoates, Alkyl 4-Ethoxy-2-oxo-3-butenoates, and Monoprotected Malonaldehydes

Article abstract of DOI:10.1055/s-1988-27541

Haloform reaction of 4-alkoxy-1,1,1-trichloro-3-buten-2-ones, which can be obtained by acylation of enol ethers, gives 3,3-dialkoxypropanoic esters.Transacetalization of ethyl 3,3-diethoxypropanoate with 2,2-dimethyl-1,3-propanediol, followed by reduction and oxidation with DMSO/oxalyl chloride yields a monoprotected malonaldehyde. 4-Ethoxy-2-oxo-3-butenoates are synthesized either by acylation of enol ethers with alkoxalyl chlorides or by Claisen condensation of alkyl pyruvates with orthoesters.