Search for dioxocarbenes in photochemical reactions of 5-diazo-4,6-dioxo-1,3-dioxanes, associated diazirines, and S-ylides

On direct photolysis of 2,2-dialkyl-5-diazo-4,6-dioxo-1,3-dioxanes in the presence of pyridine, methanol or dimethyl sulfide as carbene traps, the yield of ‘carbene’ products does not exceed 27–28%. At the same time photochemical transformations of the related 3,3-diacyldiazirines and dioxosulfonium ylides of this series, evidently, occur without generation of carbene intermediates.