Synthesis of α-oxosulfines by flash vacuum thermolysis of 2,3-dihydro-1,4-oxathin S-oxides. Photoelectron spectrum of thioxoethanal S-oxide.
Résumé
RCOCR1SO (I; R = R1 = H, Me; R = Me, R1 = H) were generated by flash vacuum thermolysis of oxathiins. I (R = R1 = H) was characterized by low-temp. IR and, in particular, photoelectron spectroscopy. The exptl. IP's, as well as MNDO calcns., agree with the proposed structure [the (E)-s-cis conformation being the most stable] and exclude the formation of the cyclic isomers β-sulfine and 3-thia-1,2-dioxole. The Me derivs. were characterized by low-temp. IR and NMR spectroscopy, and chem. trapping by 2,3-dimethyl-1,3-butadiene. [on SciFinder(R)]