Citation: N. Dekimpe et al., SYNTHESIS OF 4,4-DISUBSTITUTED BETA-LACTAMS BY REGIOSPECIFIC ELECTROPHILE-INDUCED AND SILVER-INDUCED RING EXPANSION OF 2,2-DISUBSTITUTED 1-METHOXYCYCLOPROPYLAMINES, Journal of organic chemistry, 61(19), 1996, pp. 6500-6503