1-(6'-O-t-butyldimethylsilyl-2'-C-cyano-3',4'-O-isopropylidene-2'-O-mesyl-β-D-talopyranosyl)-5-fluorouracil 在
1,8-二氮杂双环[5.4.0]十一碳-7-烯 作用下,
以
乙腈 为溶剂,
反应 36.0h,
以74%的产率得到[1-(6'-O-t-butyldimethylsilyl-3',4'-O-isopropylidene-β-D-talopyranosyl)-5-fluorouracil]-2'-spiro-5"-(4"-amino-1",2"-oxathiole-2",2"-dioxide)