Regiospecific opening of 1,2-expoxides with acetone cyanohydrin under mildly basic conditions
作者:David Mitchell、Thomas M Koenig
DOI:10.1016/s0040-4039(00)92067-7
日期:1992.6
Acetone cyanohydrin with stoichiometic triethylamine opens epoxides regiospecifically to give β-hydroxy nitriles. As expected, addition of cyanide occurs at the least substituted carbon.
The lipase mediated kinetic resolution of pharmaceutically important beta-hydroxy nitrites is described in high enantionteric excesses and good yields. Some of the chiral beta-hydroxy nitriles have been employed in the synthesis of P-adrenergic blocking agents such as propranolol, alprenolol and moprolol. This protocol has also been extended for the enantiopure preparation of 5-(4-tosyloxymethyl)-1,3-oxazolidine-2-one and 3-liydroxy-4-tosyloxybutaiieiiitrile, chiral intermediates of high synthetic value. (c) 2005 Elsevier Ltd. All rights reserved.