Intramolecular nitrile oxide–olefin cycloaddition to form hexahydrobenzisoxazole 14, which engenders a phenylsulfonyl, 2,5-difluorophenyl geminally substituted carbon substructure, proceeds with up to 99% ds. A rationalization of the high level of substrate-based stereo-induction observed in this and related ketone and acrylonitrile metallohydride reductions, supported by single crystal X-ray crystallography, is presented.
分子内氧化腈-烯烃环加成形成六氢苯并
异恶唑 14,产生苯磺酰基、2,5-二
氟苯基孪位取代的碳亚结构,收率高达 99%。提出了在单晶 X 射线晶体学的支持下,在该反应以及相关的酮和
丙烯腈金属
氢化物还原中观察到的高
水平基于底物的立体诱导的合理化。