Aromatic ring synthesis by 1,3-Michael-Claisen annulation: Application to a Trolox analogue and to Precocene II

Article abstract of DOI:10.1016/0040-4020(95)01044-0

A Trolox analogue, 3,4-dihydro-2-ethoxycarbonyl-6-methoxy-7-hydroxybenzopyran and Precocene II, were prepared from substituted α-methylene-δ-valerolactone and 1,1-bis-(methylthio)-2-propanone or butanone, via a 1,3-Michael-Claisen annulation.