SOLID-STATE PHOTOCHEMISTRY OF N,N-DIALKYL-ALPHA-OXOAMIDES - TYPE-II REACTIONS IN THE CRYSTALLINE STATE

The solid state photochemistry of N, N-dialkyl-α-oxoamides (1) has been studied. The amides undergo type II cyclization giving β-lactams(2) selectively. The selective formation of the lactams via an unprecedented type II reaction in the crystalline state is explainable in terms of the crystal lattice restraints on the molecular motion of the biradical intermediate (5) formed by γ-hydrogen abstraction. The nonreactivity of N-alkyl-a-oxoanilides toward solid state photolysis was most reasonably explained by their unfavorable s-cis geometries for γ-hydrogen abstraction. © 1979, American Chemical Society. All rights reserved.