(±)-Phycocyanobilin and its derivatives bearing a photoreactive group at D-ring were first synthesized by the development of a new and convenient method for the preparation of A-ring, transesterification for propanoic acid side-chains of the pyrrole derivative common to B- and C-rings, and deprotection of allyl ester side-chains with a palladiumcatalyst to avoid migration of exocyclic olefin of A-ring.
(±)-藻蓝胆素及其在 D 环上带有光反应性基团的衍生物首先是通过开发一种新的方便的方法来合成的,该方法用于制备 A 环,对 B 共有的吡咯衍生物的丙酸侧链进行酯交换- 和 C 环,以及使用钯催化剂对烯丙酯侧链进行脱保护,以避免 A 环的环外烯烃迁移。
Efficient Construction of A,B-Rings Component for Syntheses of Phycocyanobilin and Its Derivative
Total syntheses of phycocyanobilin and its photoactivatable derivative were accomplished by developing a new and versatile method for the construction of A,B-rings component, which consists of the Wittig-type new coupling reaction of 4-(1-methoxyethyl)-3-methyl-5-tosyl-1,5-dihydro-2H-pyrrol-2-one and a 2-formyl pyrrole derivative in the presence of nBu3P and a base, followed by reduction with aluminum amalgam and subsequent acid treatment.