A method of thioacetate deprotection by providing a compound of the formula R.sup.1--S--CO--R.sup.2, and reacting the compound with a quaternary ammonium cyanide salt in the presence of a protic solvent in an inert atmosphere to convert the compound to a product of the formula R.sup.1--SH. R.sup.1 is an organic group in which the bonding to sulfur is through a saturated carbon, and R.sup.2 is an aliphatic group.