Highly diastereoselective synthesis of (3R,4R)- and (3R,4S)-.BETA.,.GAMMA.-diamino acids from D-phenylalanine.
作者:SHINZO KANO、TSUTOMU YOKOMATSU、HARUO IWASAWA、SHIROSHI SHIBUYA
DOI:10.1248/cpb.36.3341
日期:——
(2R, 3S)-N-Boc-2-Amino-3-hydroxy-1-phenylbutane (9a) and (2R, 3S)-N-Boc-2-amino-3-hydroxy-1-phenylpentane (9b) were converted to (3R, 4R)-N3-Boc-3, 4-diaminopentanoic acid (12a) and (3R, 4R)-N3-Boc-3, 4-diaminohexanoic acid (12b) through SN2 type substitution of the hydroxy group to an amino group and oxidation of the phenyl group to a carboxyl group. In a similar way, the (3R, 4S)-isomers (18a, b) were also synthesized from (2R, 3R)-N-Boc-2-amino-3-hydroxy-1-phenylbutane (15a) and (2R, 3R)-N-Boc-2-amino-3-hydroxy-1-phenylpentane (15b), respectively, derived from (2R, 3S)-N-Cbz-2-amino-3-hydroxy-1-phenylbutane (6a) and (2R, 3S)-N-Cbz-2-amino-3-hydroxy-1-phenylpentane (6b) by means of the diastereoconversion reaction.
(2R, 3S)-N-Boc-2-氨基-3-羟基-1-苯基丁烷 (9a) 和 (2R, 3S)-N-Boc-2-氨基-3-羟基-1-苯基戊烷 (9b) 通过对羟基进行SN2型取代转化为氨基,及将苯基氧化为羧基,生成(3R, 4R)-N3-Boc-3, 4-二氨基戊酸 (12a) 和(3R, 4R)-N3-Boc-3, 4-二氨基己酸 (12b)。以类似的方式,(3R, 4S)-异构体 (18a, b) 也分别由(2R, 3R)-N-Boc-2-氨基-3-羟基-1-苯基丁烷 (15a) 和(2R, 3R)-N-Boc-2-氨基-3-羟基-1-苯基戊烷 (15b) 合成,这两者是通过二手态转化反应由(2R, 3S)-N-Cbz-2-氨基-3-羟基-1-苯基丁烷 (6a) 和(2R, 3S)-N-Cbz-2-氨基-3-羟基-1-苯基戊烷 (6b) 得到的。