K. Karupaiyan et al., SYNTHESIS OF N-1-UNSUBSTITUTED B-LACTAMS - INTRODUCING N-1-(1'-THIOPHENYL)BENZYL AS AN N-PROTECTING GROUP, Tetrahedron letters, 38(24), 1997, pp. 4281-4284
A diastereoselective synthesis of (+/-) cis-beta-lactams (5 & 6) via c
ycloaddition reaction of N-1-(alpha-thiophenyl)benzyl imines (3) with
acid chlorides (4) in the presence of triethyl amine is described. Dep
rotection of N-1-(alpha-thiophenyl)benzyl group was achieved in good y
ields by oxidation using potassium persulfate. (C) 1997 Elsevier Scien
ce Ltd.