A. Tako et al., HETEROCYCLICALLY BRIDGED TRICYCLIC BETA-LACTAMES - A SIMPLE SYNTHESISOF TRAHYDRO-3-OXA-1-AZA-CYCLOBUTA[B]NAPHTHALEN-2-ONES, Monatshefte fuer Chemie, 128(11), 1997, pp. 1149-1156
The tricylic 3,4-bridged beta-lactames 7 and 8 containing a hetero ato
m as 3-substituent of the azetidin-2-one ring were synthesized by intr
amolecular radical cyclization using cis-substituted 3-(2-bromo-arylox
y)-azetidine-2-ones 6 as precursors. These precursors were generated b
y stereospecific acid chloride-imine reaction from the corresponding s
ubstituted (2-bromophenoxy)acetic acid chlorides 2 and imine 5.