6(R)-[2-[8(S)-(2,2-dimethylbutyryloxy)-2(S)-methyl-6(S)-carboxy-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)]ethyl]-4(R)-hydroxy-3,4,5,6,tetrahydro-2H-pyran-2-one 、
氯甲酸异丁酯 在
三乙胺 作用下,
以
二氯甲烷 为溶剂,
生成 6(R)-[2-[8(S)-(2,2-dimethylbutyryloxy)-2(S)-methyl-6(S)-isobutyloxycarbonyloxycarbonyl-1,2,6,7,8,8a(R)-hexahydronaphthyl-1(S)]ethyl]-4(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one