Synthesis of a Stereoisomer of Frullanolide Utilizing the Intamolecular Cyclization of ω-Formyl-2-alkenylsilane

Article abstract of DOI:10.1246/bcsj.66.2298

Synthesis of 10-epi-frullanolide (3) is reported via the intramolecular cyclization of ω-formyl-α-trimethylsilylmethyl-α,β-unsaturated ester.The cyclization precursor, ethyl (Z)-5-(2-formyl-1,3-dimethyl-2-cyclohexenyl)-2-trimethylsilylmethyl-2-pentenoate (17), was prepared from 2,6-dimethyl-2-cyclohexen-1-one through the dialdehyde monoacetal as the key intermediate.Cyclization of 17 with tetrabutylammonium fluoride produced the hydroxy ester having C(6α)-H and C(7β)-H, which was hydrolyzed, then subjected to Fujisawa's lactonization to afford 3.