Synthesis and absolute configuration of chiral (C<sub>3</sub>) cyclotriveratrylene derivatives. Crystal structure of (M)-(–)-2,7,12-triethoxy-3,8,13-tris-[(R)-1-methoxycarbonylethoxy]-10,15-dihydro-5H-tribenzo[a,d,g]-cyclononene
作者:André Collet、Jacqueline Gabard、Jean Jacques、Michèle Cesario、Jean Guilhem、Claudine Pascard
DOI:10.1039/p19810001630
日期:——
p. 127 °C, [α]D25–16.1°(CHCl3). The crystal and molecular structure of (–)-(3) have been determined by single crystal X-ray analysis: orthorhombic, a= 23.428, b= 22.165, c= 15.145 Å space group P212121, Z= 8. The M absolute configuration has been ascribed to (–)-(3), on the basis of internal comparison with groups –CH(Me)CO2Me whose absolute stereochemistry is derived from that of (+)-(5b). Seven chiral
如下明确地确定了手性C 3-环三偏戊二烯衍生物的绝对构型。首先,通过化学相关性和圆二色性测定,将2-(2-乙氧基-4-羟甲基苯氧基)丙酸(5b)的绝对构型确定为R -(+)。经高氯酸处理后,化合物(+)-(5b)生成标题化合物(-)-(3),以14%的产率分离,熔点为127°C,[α] D 25 –16.1°(CHCl 3) 。(–)-(3)的晶体和分子结构已通过单晶X射线分析确定:正交晶体,a = 23.428,b = 22.165,c = 15.145Å空间群P 2 1 2 1 2 1,Z =8。根据与–CH(Me)CO 2 Me族的内部比较,M的绝对构型归因于(–)-(3)。 (+)-(5b)的值。七个手性C 3-环三藜芦烯衍生物已与(M)-(-)-(3)化学相关。这样建立的绝对构型与从圆二色性光谱的激子分析中独立推导的构型相同。