乙酸酐 、 Acetic acid (4aR,7aS,9cS)-1-acetoxy-7,7,9c-trimethyl-2-propyl-4a,5,6,7,7a,8,9,9c-octahydro-phenanthro[4,5-bcd]furan-3-yl ester 在
三氟化硼乙醚 作用下,
生成
Acetic acid (S)-6,8-diacetoxy-1,1,4-trimethyl-7-propyl-1,2,3,9,10,10a-hexahydro-benzo[f]azulen-5-yl ester