Retinol analogues. Part I. Synthesis of acyclic analogues of retinoic acid

Abstract

Various C₁₉ analogues of retinoic acid have been prepared from isopropyl t-butyl ketone. Potassium hydrogen sulphate in dimethyl sulphoxide proved an effective reagent for the elimination of water from intermediate hydroxyderivatives, but dehydration of 9-hydroxy-6,10-dimethyl-9-t-butylundeca-3,5,7-trien-2-one yielded 2-methyl-5-(4-isopropyl-1,5,5-trimethylhexa-1,3-dienyl)furan and 9-isopropyl-6,9,10-trimethylundeca-3,5,7,10-tetraen-2-one.