PREPARATION AND ALKYLATION OF CYCLIC β-TRIMETHYLSTANNYL α,β-UNSATURATED ESTERS. A NEW, GENERAL ANNULATION SEQUENCE

Article abstract of DOI:10.1016/S0040-4039(01)90996-7

The key steps of a newly developed annulation method involve (a) reaction of cyclic β-trifluoromethanesulfonyloxy α,β-unsaturated esters (e.g. 14-16) with lithium(phenylthio)(trimethylstannyl)cuprate, (b) alkylation of the resultant products (e.g.17-19) with 1,ω-dihaloalkanes, and (c) transmetalation-cyclization of suitable substrates (e.g.25, 26, 28, 30) derived from the alkylation products (e.g. 20-24).