1,2,3,4-di-O-isopropylidene-α-D-galactooct-6-enopyrannuronate d'ethyle 、
噻莫西酸 、
苊醌 以
甲苯 为溶剂,
反应 5.0h,
以76%的产率得到ethyl (5R,6S,7R)-2'-oxo-7-[(1S,2R,6R,8R,9S)-4,4,11,11-tetramethyl-3,5,7,10,12-pentaoxatricyclo[7.3.0.02,6]dodecan-8-yl]spiro[3,6,7,7a-tetrahydro-1H-pyrrolo[1,2-c][1,3]thiazole-5,1'-acenaphthylene]-6-carboxylate