Diastereoselectivity in Mn(III)-promoted 4-exo-trig cyclization of enamides to beta-lactams
[reaction: see text] The effect of chiral substituents on the enamide nitrogen atom upon the diastereoselection of the Mn(III)-mediated 4-exo-trig cyclization to beta-lactams was studied. A significant level of diastereoselectivity was achieved when an amino acid ester moiety was included into the enamidic skeleton. The structure of the major diastereoisomer was suggested by semiempirical calculations.
D'Annibale
A
Centro CNR C.S.C.S.O.N., Dipartimento di Chimica, Universita degli Studi La Sapienza, Roma, Italy. dannibale@axrma.uniroma1.it
Nanni
D
Trogolo
C
Umani
F