| 摘要 |
This application provides an alkoxide of the formula: where, for example, M is a metal; R15 is hydrogen; R16 is a lower alkanoyloxy group; R17 and R18 form an oxo group; R19 is hydrogen; R20 is a lower alkanoyloxy group; R21 is a hydrogen group; R22 and R23 form an oxetane ring; R24 is a lower alkanoyloxy group; R25 is an aryloyloxy group; R26 is a hydrogen group; and R27 is a hydroxy group. The invention also provides a .beta.-lactam of the formula: where, for example, R1 is an alkoxy group, R2 is hydrogen, R3 is hydrogen, R4 is an alkyl group, and R5 is a -COOR10 group, where R10 is an alkyl group. |
