作者:Makoto Oba、Yosuke Demizu、Nanako Yamagata、Yukiko Sato、Mitsunobu Doi、Masakazu Tanaka、Hiroshi Suemune、Haruhiro Okuda、Masaaki Kurihara
DOI:10.1016/j.tet.2010.02.003
日期:2010.3
a=10.470 Å, b=10.953 Å, c=32.405 Å, Z=4, R1=0.040, and Rw=0.046. In the asymmetric unit of 1, the homochiral l-Pro1-l-Pro2 adopts a polyproline II structure, which induces a left-handed (M) 310-helical structure in the following -(Aib)4- sequence. The preferred conformation of diastereomeric 2, which contains heterochiral d-Pro1-l-Pro2 segments, was similar to that of 1 with differences at the N-terminal
2非对映异构-Pro-亲(AIB)的晶体结构4 -序列,CBZ-升-Pro-升-Pro-(AIB)4 -OMe(1)和CBZ- d -Pro-升-Pro-(Aib取代)4- OMe(2),已经通过X射线晶体学分析确定。这两种化合物的晶体通过下列参数表征:(1)单斜晶,P 2 1,一个= 10.543埃,b = 8.103埃,c ^ = 22.642埃,β = 97.679,Ž = 2,- [R 1 = 0.104,和R w = 0.327;(2)正交晶,P 2 1 2 1 2 1,a= 10.470,b= 10.953,c= 32.405,Z= 4,R 1= 0.040,R w= 0.046。在的不对称单元1中,纯手性升-Pro 1 -升-Pro 2采用聚脯氨酸II结构,其诱导左手(中号)3 10在下文中螺旋结构- (AIB)4- 顺序。非对映体的优选构象2,其含有异向d -Pro 1 -升-Pro