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US 5,292,946 AGranted
In-situ preparation of diisopinocamphenyl chloroborane
AssigneeMerck & Co., Inc.
InventorsPamela M. Simpson, David M. Tschaen, Thomas R. Verhoeven
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Abstract
The present invention is directed to in-situ preparation of diisopinocamphenylchloroborane, and the use of same in the reduction of prochiral ketones to optically active alcohols such as those of formula B. ##STR1## The compound of Formula B is useful in the production 2,5-diaryltetrahydrofurans useful as PAF antagonists.
Claims4
A process of making diisopinocampheylchloroborane comprising:
- (a) contacting borane methylsulfide in an etheral solvent with (1R)-(+)-.alpha.-pinene, having optical purity of between about 91% ee to 95% ee, to form the diisopinocampheylborane of Formula I, ##STR39## (b) contacting, without further purification, the impure product of step (a) with an acidic chloride to yield diisopinocamphenylchloroborane of Formula 2;
- ##STR40##
Dependencies are inferred from the claim text.