The synthesis of a number of stable acyloxymethyl carbonochloridates 7 has been accomplished in four steps from chloromethyl carbonochloridate 3. Each step has been optimized with propanoyloxymethyl carbonochloridate 7c as a model compound (64% overall yield). Diethyl ether-boron trifluoride catalyzes the conversion of carbonothioate 6cc to the carbonochloridate 7c by chlorination with sulfuryl chloride. Acylation of a few compounds containing hydroxy or amino groups by 7c is described.