[摘要]:A range of alkenes were converted in a single step into the corresponding trifluoromethyl-substituted cyclopropanes by treatment with 2-diazo-1,1,1-trifluoroethane over metal catalysts. Application of the Gaspar-Roth procedure allowed the prepn. of the target compds. on a multi-gram scale. The practical utility of this reaction was demonstrated by the synthesis of both diastereoisomers of the non-natural amino acid trifluoronorcoronamate in 2 steps.