Regio- and stereoselective 1,6-photocyclization of aspartic acid- derived chiral γ-ketoamides[1]

Article abstract of DOI:10.1016/S0040-4039(99)00448-7

Chiral α-acylamino γ-ketoamides 2 were irradiated and regioisomeric 1,6-cyclization products 3 and 4 obtained in high yields. Symmetrically N,N- disubstituted substrates 2a,b reacted diastereoselectively to give the all- cis products 3a,b in high yields. High 1,3-asymmetric induction was also observed for the unsymmetrically N,N-disubstituted 2d and 2e. The stereoselectivity of these reactions is discussed in terms of SOC-controlled spin inversion geometries.