Ketene mercaptals, of the general formula CHFC (SR)~, have been relatively unknown. Rothstein'has reported the preparation of methyl ketene diethyl mercaptal by the abnormal dehydrohalogenation of p-chloropropionaldehyde diethyl mercaptal. This proposed ketene dimercaptal structure has since been questioned by Parham.* Ketene dimethyl mercapt, al has been disclosed3 as a pyrolysis product in a patent concerned with sulfur-containing ...