A Practical Synthesis of (2S, 3R)-3-Amino-2-methylpentanoic Acid fromL-Aspartic Acid
作者:Charles W. Jefford、James McNulty
DOI:10.1002/hlca.19940770807
日期:1994.12.14
L-Aspartic acid by successive N-tosylation, anhydride formation, and reduction was converted into (3S)-3-(tosylamino)butano-4-lactone (4). Electrophilic methylation of 4, subsequent iodo-esterification and nucleophilic methylation, followed by saponification and deprotection, gave (2S, 3R)-3-amino-2-methylpentanoic acid (2) with an ee of > 99% in seven steps and in an overall yield of 34%.
通过连续的N-甲苯磺酸化,酸酐形成和还原将L-天冬氨酸转化为(3S)-3-(甲苯磺酰基氨基)丁烷-4-内酯(4)。4的亲电甲基化,随后的碘化酯化和亲核甲基化,然后进行皂化和脱保护,在七个步骤中得到ee> 99%的(2 S,3 R)-3-氨基-2-甲基戊酸(2)和总产率为34%。