A new method for protecting alcohols as tert-butyl ethers is reported. The reaction is performed in tert-butyl acetate in the presence of a catalytic amount of HClO 4 . The process is extremely efficient and primary and secondaryalcohols as well as diols are protected under very mild conditions. Remarkably, tert-butyl acetate can be easily recovered after the workup of the reaction and recycled.
The unknown tert-butyl esters 2a,b and -ethers 4a,b of otherwise nonsubstituted optical pure (R,R)-tartaricacid are synthesized. Esters are made by reaction of 0,0-di-acyl protected tartaric acid with isobutene and selective cleavage via transesterification of the protective groups. Ethers are formed by reaction of dibenzyl tartrate with isobutene followed by hydrogenolysis of the benzyl groups. Saponification