Retinoids and Related Compounds. VII. Synthesis of Retinoidal 4-Ylidenebutenolides and Their Homologues

Abstract

Retinoidal ylidenebutenolides (XVIa, b and XVIIa, b) and their homologues have been synthesized in several steps starting from β-cyclocitral (IIIa) or 3-methoxy-β-cyclocitral (IIIb). The spectral characteristics of the 4-ylidenebutenolides (II) are described in comparison with those of methyl all-(E)-retinoate (XX).