Matrix isolation and photochemistry of α-diazo sulfoxides: Formation of α-oxo sulfine as an intermediate

The photochemistry of the α-diazo sulfoxides 1a and 1b has been investigated in solid argon at 10 K by IR and UV/Vis spectroscopy. Both diazo compounds react to form sulfine 2a by photochemically induced hereto Wolff rearrangement of sulfinyl carbene 3, which itself cannot be detected in solid argon. Irradiation at λ > 320 nm results in decomposition of the sulfine 2a to give 2-oxa-4-thiabicyclo[4.4.0]decane-3.5-dione (5) and 7-oxabicyclo[4.2.0]octan-8-one (6) under abstraction of COS. The matrix-isolated species have been identified by comparison of experimental and calculated IR spectra.