LITHIUM-B-ISO-2-ETHYLAPOPINOCAMPHEYL-9-BORABICYCLO[3.3.1]NONYL HYDRIDE AS AN IMPROVED REAGENT FOR ASYMMETRIC REDUCTION OF UNHINDERED ALIPHATIC-KETONES - FURTHER EVIDENCE FOR THE IMPROVED ENANTIOSELECTIVITY IN REDUCTIONS BY REAGENTS CONTAINING INCREASED STERIC REQUIREMENTS AT THE 2-POSITION OF THE APOPINENE STRUCTURE

被引:21
作者
RAMACHANDRAN, PV
BROWN, HC
SWAMINATHAN, S
机构
[1] H.C. Brown and R.B. Wetherill Laboratories of Chemistry, Purdue University, West Lafayette
关键词
D O I
10.1016/S0957-4166(00)86346-6
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
Lithium B-iso-2-ethylapopinocampheyl-9-borabicyclo[3.3.1]nonyl hydride (Eapine-Hydride), prepared by hydroboration of 2-ethylapopinene with 9-borabicyclo[3.3.1]nonane, followed by treatment with tert-butyllithium, is as effective as NB-Enantride for the chiral reduction of prochiral ketones. For example Eapine-Hydride reduces 2-octanone, 3-methyl-2-butanone, and acetylcyclohexane in 77% (75%, 79%), 77%, (68%), and 80% (80%) ee, respectively, at -100°C. (Values in parenthesis are for NB-enantride). © 1990.
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页码:433 / 436
页数:4
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