(3aS,4S,5S,6aR)-5-(oxan-2-yloxy)-4-[(E,3S)-3-(oxan-2-yloxy)-4-phenoxybut-1-enyl]-3,3a,4,5,6,6a-hexahydrocyclopenta[b]furan-2-one 生成 (3aR,4R,5R,6aS)-5-(oxan-2-yloxy)-4-[(E,3S)-3-(oxan-2-yloxy)-4-phenoxybut-1-enyl]-3,3a,4,5,6,6a-hexahydro-2H-cyclopenta[b]furan-2-ol