Ethyl chloroacetate, glycidic esters from

The Cl 4-aldehyde 7 is also a key intermediate in the technical synthesis of vitamin A. It can be prepared from p-ionone f7J in a Darzens glycidic ester condensation by the reaction with ethyl chloroacetate (16) via 17 as intermediate. The chain elongation to the Ci9-aldehyde 72 was achieved by reaction with the acetylenic Cs-compound 18 (Scheme 4). 

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