Reaction of aspartic acid derivatives with Grignard reagents—synthesis of γ,γ-disubstituted α- and β-amino-butyrolactones
作者:Thomas Brinkmann、Alfred Gilg、Andreas Hamm、Hendrik Lüsch、Guido Morbach、Horst C Uzar
DOI:10.1016/s0957-4166(00)00344-x
日期:2000.9
A series of γ,γ-dimethyl and γ,γ-diphenyl substituted α- and β-amino-butyrolactones have been prepared in enantiomerically pure form using l-aspartic acid as a chiral building block. For the final Grignard reaction the difference in chemical reactivity between the carboxyl groups of aspartic acid was increased or inverted by preparing the corresponding semiesters, diesters and anhydrides. The resulting
使用1-天冬氨酸作为手性构件,以对映体纯的形式制备了一系列的γ,γ-二甲基和γ,γ-二苯基取代的α-和β-氨基丁内酯。对于最终的格氏反应,天冬氨酸的羧基之间的化学反应性差异通过制备相应的半酯,二酯和酸酐而增加或反转。在大多数情况下,在处理过程中,所得到的羟基酸和羟基酯被内酯化。因此,(2S)-2-乙氧基羰基氨基琥珀酸-4-甲酯1与甲基碘化镁反应形成(3S)-3-乙氧基羰基氨基-5,5-二甲基-四氢呋喃-2-酮2b。获得了两个有趣的副产物,发现它们是由C-1羧酸而不是C-4羧酸酯基团的进攻所导致的,从而导致了(3 S)-3-乙氧基羰基氨基-4-氧代戊酸甲酯3和( 4 S)-4-乙氧基羰基氨基-5,5-二甲基-四氢呋喃-2-酮5a。