DIHYDROFURAN AND TETRAHYDROFURAN BUILDING-BLOCKS FROM 1,4 3,6-DIANHYDROMANNITOL .1. SYNTHESIS OF (1S,5R,7R)-ENDO-(-)-BREVICOMIN AND (1S,5R,7S)-(-)-EXO-BREVICOMIN AND (R)-(+)-DODECANOLIDE/

The eliminative ring fission of iodides derived from 1,4:3,6-dianhydro mannitol3 has been exploited for preparing three enantiomerically pure species, 1-3, which feature a di-or tetrahydrofuran moiety and one or two stereogenic centers. These species are extremely versatile buildi ng blocks for the construction of natural products. Their potential wa s demonstrated by the synthesis of the title insect pheromones.