Nuclear modification of clavulanic acid. The preparation of two 4,7-fused β-lactam systems
作者:Gerald Brooks、Eric Hunt
DOI:10.1039/p19830000115
日期:——
converted into the lithium carboxylates via hydrogenolysis. In an unsuccessful attempt to prepare one of these 4,7-fused ring systems, compound (2) was found to react with triethylamine to give two 14-membered ring compounds, dibenzyl (7RS, 16RS)-3,12-dihydroxy-9,18-dioxo-6,15-dioxa-1,10-diazatricyclo[14.2.0.07,10]octadeca-2,11-diene-2,11-dicarboxylate and its (7RS, 16SR)-isomer.
4,7-稠合的β-内酰胺化合物3-甲氧基-9-氧代-6-氧杂-1-氮杂-氮杂双环[5.2.0]壬-2-烯-2-羧酸酯和3-甲氧基-9-氧代苄基苄基6-oxa-1-氮杂双环[5.2.0] nona-2,4-二烯-2-羧酸酯的制备方法是利用棒酸苄酯的总碳氧骨架(2)。类似地,从棒酸4-硝基苄基酯制备相应的4-硝基苄基酯,并通过氢解将其转化为羧酸锂。在尝试制备这些4,7稠合的环系统之一的尝试失败时,发现化合物(2)与三乙胺反应生成了两个14元环化合物,即二苄基(7 RS,16 RS)-3,12-二羟基-9,18-dioxo-6,15-dioxa-1,10-二氮三环[14.2.0.0 7,10] octadeca-2,11-二烯-2,11-二羧酸酯及其(7 RS,16 SR)-异构体。