Selective methylene C–H oxidation for the synthesis of alcohols with a broad scope and functional group tolerance is challenging due to the high proclivity for further oxidation of alcohols to ketones. Here, we report the selective synthesis of benzylic alcohols employing bis(methanesulfonyl) peroxide as an oxidant. We attempt to provide a rationale for the selectivity for monooxygenation, which is
Stereocontrolled synthesis of β-hydroxyphenylalanine and β-hydroxytyrosine derivatives
作者:Christopher J. Easton、Craig A. Hutton、Peter D. Roselt、Edward R.T. Tiekink
DOI:10.1016/s0040-4020(01)85256-x
日期:1994.1
Side-chain bromination of N-phthaloyl-(S)-phenylalanine and tyrosine derivatives, followed by treatment of the product bromides with silver nitrate in aqueous acetone, affords the corresponding (2S,3R)-beta-hydroxy-alpha-amino acids, enantiospecifically and diastereoselectively. The diastereoselectivity depends on the carboxyl protecting group, tert-Butyl esters display greater stereoselectivity than the corresponding methyl esters, presumably as a result of a steric effect, while N-tert-butylamides react diastereospecifically due to a combination of steric and electronic effects.