Summary: Alcohols (ROH) may be converted into their MTMEC deri_vatives (6) by acylation with 2-(methylthiomethoxyJethoxycarbony1 chloride (2); the MTMEC" protected protecting group" may be removed by treatment first with Hg (I1) perchlorate in the presence of 2, 4, 6- collidine or pyridine in acetone-water solution, followed by hydrolysis under very mild basic conditions.