The pyrolysis of a number of symmetrical sulfite esters of primary and secondary alcohols has been studied. Decomposition to evolve sulfur dioxide begins at temperatures ranging from 130'for a-methylbenzyl sulfite to 250 O for phenethyl sulfite. The urinciual mode of decomDosition is to form olefin and alcohol. Formation of ether was observed onlv in two cases as a mindr pro& of the reaction. In the case of n-amyl sulfite