Haem d1: stereoselective synthesis of the macrocycle to establish its absolute configuration as 2R,7R 1
作者:Jason Micklefield、Marion Beckmann、Richard L. Mackman、Michael H. Block、Finian J. Leeper、Alan R. Battersby
DOI:10.1039/a700655a
日期:——
Although the gross structure of haem d1 1 has
been established, the absolute stereochemistry at C-2 and C-7 is
unknown. An unambiguous stereoselective synthesis of the ester of the
metal-free macrocycle corresponding to haem d1 has
been completed which establishes the absolute configuration of the
natural cofactor as 2R,7R. Haem d1
is thus shown to match stereochemically other biologically important
macrocycles, e.g. those involved in the biosynthesis of vitamin
B12, which are related to isobacteriochlorins and also
display 2R,7R configurations. The synthetic sequence
used is based on a new procedure for assembly of the western and eastern
building blocks and it serves as an efficient general route for
construction of isobacteriochlorins.
虽然血红素 d1 1 的总体结构已经确定,但 C-2 和 C-7 的绝对立体化学结构尚不清楚。我们完成了血红素 d1 对应的无金属大环的酯的明确立体选择性合成,确定了天然辅助因子的绝对构型为 2R、7R。因此,血红素 d1 在立体化学上与其他重要的生物大环相匹配,例如那些参与维生素 B12 生物合成的大环,它们与异菌氯蛋白有关,也显示出 2R、7R 构型。所使用的合成序列是基于一种组装西部和东部结构单元的新程序,它是构建异细菌氯蛋白的有效通用路线。