Synthesis and stereochemical analysis of β-nitromethane substituted γ-amino acids and peptides
作者:Mothukuri Ganesh Kumar、Sachitanand M. Mali、Hosahudya N. Gopi
DOI:10.1039/c2ob27070f
日期:——
β-unsaturated γ-amino esters and the Michael addition products suggests that an H–Cγ–CβCα eclipsed conformer of the unsaturated amino ester leads to the major (anti) product compared to that of an N–Cγ–CβCα eclipsed conformer. The major diastereomers were separated and subjected to the peptide synthesis. The single crystal analysis of the dipeptide containing β-nitromethane substituted γ-amino acids reveals
迈克尔加成中的高非对映选择性 硝基甲烷对于α,β-不饱和γ-氨基酯,研究了β-硝基甲烷取代的γ-氨基酸和肽的晶体构象。结果表明,N- Boc保护的酰胺NH,α,β-不饱和γ-氨基酯的构型和烷基侧链在决定硝基甲烷向E-乙烯基氨基酸酯的高非对映选择性中起着至关重要的作用。两个α,β不饱和γ氨基酯和迈克尔加成产物的晶体构象的研究表明,一个H-C γ -C β Ç α黯然失色不饱和氨基酯导致主要(的构象异构体的抗)产品相比那的N-C γ -C β ç α黯淡的构想者。分离主要的非对映异构体并进行肽合成。含有β-硝基甲烷取代的γ-氨基酸的二肽的单晶分析揭示了螺旋形的折叠构象,带有一个涉及九个原子假环的分离的H键。