1.5-Dienes from allylic alcohols and carbonyl compounds by successive Claisen rearrangement, Wittig reaction, and Cope rearrangement: an attempted synthesis of ‘propylure’

Abstract

3,3-Dialkylallyl alcohols and aldehyde dimethyl acetals condense with Claisen rearrangement to form substituted pent-4-enals. The hexa-1,5-dienes made from these aldehydes by the Wittig reaction then rearrange in the opposite direction according to Cope. While this scheme worked very well with n-heptanal dimethyl acetal and 3-methylbut-2-en-1-ol, yielding 2-methyldodeca-2,6-diene, it was less successful when applied to an attempted synthesis of ‘propylure’[(5E)-10-propyltrideca-5,9-dienyl acetate].