A STUDY OF METHYL AND TERT-BUTYL AS NON MIGRATING GROUPS IN THE REACTION OF ME(ORGANYL)ZINC AND T-BU(ORGANYL)ZINC WITH ALDEHYDES

A series of mixed methyl (organyl) and tert-butyl(organyl)zincs were prepared by reaction of ZnCl2 with Grignard reagents. In the presence of salts t-butyl migrates to a lessor extent than methyl in the reaction with aldehydes. In the absence of salts both groups are comparable. BuZnMe prepared under salt-free conditions adds to benzaldehyde in 82.4 % ee and in 85 % yield, comparable to the reaction with distilled dibutylzinc.