Characterisation of novel 3-carboxyalkyl-steranes occurring in geological samples
摘要:
Three novel series of 3-carboxyalkyl-steranes have been identified by synthesis in sediments from an evaporitic basin. These compounds may derive from precursor steroids bearing a polyfunctionalised side-chain at C-3, yet unknown in living organisms. Geochemical data suggest a microalgal or a bacterial origin.
Montmorillonite Clay Catalysis. Part 2.1 An Efficient and Convenient Procedure for the Preparation of Acetals catalysed by Montmorillonite K-10
作者:Tong-Shuang Li、Sheng-Hui Li、Ji-Tai Li、Hui-Zhang Li
DOI:10.1039/a605661j
日期:——
Acetalization of aldehydes and ketones is catalysed
by montmorillonite K-10 in refluxing benzene or toluene in
excellent yields.
醛和酮的缩醛反应在沸腾的苯或甲苯中由膨润土 K-10 催化,产率极高。
STEROIDS: VI. THE STEREOCHEMISTRY OF 4-ETHYL-4-METHYLCHOLEST-5-EN-3-ONE (II)
作者:George Just、Keith St. C. Richardson
DOI:10.1139/v64-064
日期:1964.2.1
The stereochemistry of the title compound was determined.
标题化合物的立体化学结构已确定。
Reactions of epoxides—I
作者:J.M. Coxon、M.P. Hartshorn、D.N. Kirk
DOI:10.1016/s0040-4020(01)90832-4
日期:1964.1
The epimeric 4,5-epoxides derived from 4-methylcholest-4-en-3-one and 3α- and 3β-acetoxy-4-methylcholest-4-enes have been rearranged with boron trifluoride. Each of the six epoxides exhibits its own distinctive pattern of behaviour.
4β,5β-Epoxy-4α-methylcholestane undergoes rearrangement with boron trifluoride to give mainly 5-methyl-5α-cholestan-4-one. Under similar conditions the 4α,5α-epoxide gives the 5β-methyl-A-nor-B-homo-6-ketone (VI), which rearranges on prolonged treatment with boron trifluoride to give 5-methyl-5β-cholestan-4-one.