Photochemical isomerization of O-allyl and O-but-3-enyl thiocarbamates

The photochemistry of O-allyl and O-but-3-enyl thiocarbamates has been studied. Photolysis of benzene solutions of O-allyl N-phenylthiocarbamates gave S-allyl N-phenylthiocarbamates. The 1,3-allyl migration from the oxygen to the sulfur involves a concerted process. The same type of 1,3-migration took place in the conversion of O-benzyl N-phenylthiocarbamate into S-benzyl N-phenylthiocarbamate. Irradiation of O-but-3-enylthiocarbamates produced iminooxolanes via aminothietane intermediates. In the case of O-but-3-enyl N-benzoyl-N-phenylthiocarbamates, 3-(benzoylsulfanylmethyl)-2-phenyliminooxolanes were obtained via a ring opening of the aminothietanes involving a 1,5-benzoyl shift.