Carbamoyl derivatives of photolabile benzoins, particularly of 3′, 5′-dimethoxybenzoin, are readily prepared via the mixed p-nitrophenyl carbonate of the benzoin. The method is most suitable for secondary amines, since many primary amines exist in varying proportions as the cyclic hydroxyoxazolidinone tautomer. In alkaline solution (0.2 M NaOH) the carbamates of unsymmetrical benzoins are readily equilibrated. Flash photolysis of 3′, 5 ...
