[摘要]:A stereoselective synthesis of the normethyl C(1)-C(13) fragment of bistramide A is described. The key steps involve asym. Sharpless epoxidn., cross-metathesis reaction, and intramol. oxa-Michael reaction. The trans-2,6-disubstituted tetrahydropyran subunit was synthesized in an overall yield of 7% with 96% ee. The cis isomer was prepd. by a similar pathway with the same efficiency and enantioselectivity.