SYNTHETIC STUDIES ON ELECTRON-TRANSPORT INHIBITORS .1. CHIRAL SYNTHESIS OF A SYNTHON FOR MYXALAMIDE-D, PIERICIDIN-A, AND THE ACTINOPYRONES

The trimethylsilyl enolate 9 of (1'R,2'S)-N-methylephedrine propionate was condensed with tiglic aldehyde to afford the (1'R,2'S,2S,3R)-ester 10 with high stereoselectivity; conversion into the aldehyde 12 was effected without epimerisation, and the sequence 12 --> 13 --> 15 --> 19 --> 20 afforded in 84% e.e. the (+)-(4R,5R,2E,6E)-sulphone 20, a synthon for the electron transport inhibitors piericidin A 2 and myxalamide D 4, as well as the actinopyrones 5.