Synthesis and biological evaluation of optically active 3-H-1-carbacephem compounds.
作者:Takehiro OGASA、Hiromitsu SAITO、Yukio HASHIMOTO、Kiyoshi SATO、Tadashi HIRATA
DOI:10.1248/cpb.37.315
日期:——
Horner-Emmons cyclization. Optically active 3-H-1-carbacephem compounds were efficiently prepared by employing a penicillin acylase-producing microorganism in two ways. That is, the 7-phenylacetamide of a racemic carbacephem nucleus was hydrolyzed enantioselectively with the enzyme to afford the optically pure nucleus, which was then acylated to give antimicrobial compounds. Alternatively, a racemic
通过2 + 2环加成,然后进行分子内Horner-Emmons环化,制备具有或不具有2个α-或2个β-甲基的3-H-1-Carbacephem核。通过以两种方式使用产生青霉素酰基转移酶的微生物,可以有效地制备旋光的3-H-1-卡巴西姆化合物。即,将外消旋羧苄核的7-苯基乙酰胺用该酶对映选择性地水解,得到光学纯的核,然后将其酰化,得到抗菌化合物。或者,用该酶直接和对映选择性地将消旋的羧苄基核苯基糖基化。3-H-1-Carbacephemem核似乎是青霉素酰基转移酶比天然来源的penam或cephem核更好的底物。3-H-1-Carbacephemem化合物显示出有效的抗菌活性;化合物32a显示出的活性与头孢唑肟相当,后者是具有相同酰基的头孢烯类似物。令人感兴趣的是,事实证明,3-H-1-碳环糊精化合物比其3-取代的甲基类似物具有更强的抗菌活性。