A COMPARISON OF (CHLOROMETHYL)ZINC AND (IODOMETHYL)ZINC CYCLOPROPANATION REAGENTS

被引:246
作者
DENMARK, SE
EDWARDS, JP
机构
[1] Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana
关键词
D O I
10.1021/jo00025a007
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
A study comparing the rate of cyclopropanation of a range of olefins using (chloromethyl)- and (iodomethyl)zinc reagents is described. The (chloromethyl)zinc reagent derived from diethylzinc and chloroiodomethane is generally more reactive than the (iodomethyl)zinc analogue. The use of 1,2-dichloroethane as the solvent for these reactions was shown to be a crucial factor necessary to achieve clean, rapid, high-yielding cyclopropanations. The well-known directing effect of proximal oxygen substituents on the stereochemical outcome of "Simmons-Smith" cyclopropanations was shown to hold for the (chloromethyl)zinc reagent as well. The diethylzinc/chloroiodomethane reagent system in 1,2-dichloroethane should prove to be a valuable alternative to traditional (iodomethyl)zinc-based cyclopropanation reagents.
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页码:6974 / 6981
页数:8
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