O. Sakurai et al., NOVEL SYNTHETIC APPROACH TO CARBAPENEMS UTILIZING AZA-COPE MANNICH CYCLIZATION, Journal of the Chemical Society, Chemical Communications, (24), 1995, pp. 2527-2528
Treatment of chloride 10 with silver tetrafluoroborate afforded aldehy
de 11, which was converted to beta-ketoester 12, via tandem C-1-C-5 an
d C-2-C-3 bond formation.