Sengupta, Pasupati; Sen, Manju; Sarkar, Arup, Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1987, vol. 26, # 1-12, p. 611 - 615
Sengupta, Pasupati; Sen, Manju; Sarkar, Arup, Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1987, vol. 26, # 1-12, p. 611 - 615
Base-catalysed fragmentation of 5,6β-epoxy-3β-hydroxy-5β-cholestan-19-al
作者:Harold Mastalerz、Peter Morand
DOI:10.1039/p19820000799
日期:——
Under basic conditions, 5,6β-epoxy-3β-hydroxy-5β-cholestan-19-al (1) underwent fragmentative elimination of the 10β-function, whereas the isomeric 5α,6α-epoxide (9) underwent diaxial opening of the epoxy-group. The 1H n.m.r. spectrum of the 5β,6β-epoxide (1) and the reactivity of its 3β-methoxy-derivative (4) indicate that the fragmentation involves chelation between an intramolecular 3,19-hemiacetal
在碱性条件下,5,6β-环氧-3β-羟基-5β-胆甾醇-19-al(1)会部分地消除10β-官能团,而异构体5α,6α-环氧化合物(9)会进行双轴环氧打开-团体。5β,6β-环氧化物(1)的1 H nmr光谱及其3β-甲氧基衍生物(4)的反应活性表明,断裂涉及分子内3,19-半缩醛(22)与环氧化物氧之间的螯合,具有椅子状的过渡状态 从5β,6β-环氧化合物(1)的酸催化反应和热反应获得的产物类似地涉及分子内半缩醛(22)。
SENGUPTA, PASUPATI;SEN, MANJU;SARKAR, ARUP;DAS, SAKTIPADA, INDIAN J. CHEM., 26,(1987) N 7, 611-615