[structure: see text]. The syntheses of three fragments, 2, 3, and 4, of amphidinolide B1 have been accomplished. The 1,3-isomerization of allylic alcohol 10 was accomplished via rhenium oxo catalysis and has been applied successfully in the synthesis. (-)-MIB-catalyzed asymmetric vinylzinc addition to aldehyde 31 and the regio- and stereoselective epoxidation of unsymmetrical divinyl methanol 32 were key steps.