已经确定了从大豆胞囊线虫的芸豆孵化刺激提取物中分离出的三种新化合物甘氨酸环素 A、B 和 C 的结构。通过使用光谱方法,特别是通过差异 NOE 技术解析结构,并通过 X 射线衍射分析确认。这些结构的特点是 (1) C 和 D 环中两个甲基的迁移,(2) B 环氧化裂解失去一个碳原子和 (3) 7-氧杂双环 [2.2.1] 的存在与环阿烷烃相比,A环中的庚烷系统被视为戊烷-(GEA)或去甲三萜(GEB和GEC)。
Preparation of 2-exo-Hydroxy-7-oxabicyclo[2.2.1]heptanes
申请人:Shell Oil Company
公开号:US04487945A1
公开(公告)日:1984-12-11
2-exo-Hydroxy-7-oxabicyclo[2.2.1]heptanes are prepared by treating the corresponding cis-epoxycyclohexanol with acid in an inert solvent or by treating a 3-cyclohexen-1-ol which will produce the corresponding cis-epoxy alcohol successively or concurrently with an oxidizing agent and an acid in an inert solvent.
Cyclohexenol annulation via the alkoxy-accelerated rearrangement of vinylcyclobutanes
作者:Rick L. Danheiser、Carlos Martinez-Davila、Howard Sard
DOI:10.1016/s0040-4020(01)93268-5
日期:——
efficient method for the synthesis of 3-cyclohexenol derivatives. 2-Vinylcyclobutanones are prepared from α,β-unsaturated carbonyl compounds by the method of Trost and via [2 + 2]-cycloadditions of olefins and vinylketenes. Addition of hydride or alkyllithium reagents then generates 2-vinylcyclobutanol salts which directly rearrange to afford 3-cyclohexenols. The two methods constitute new [3 + 3]- and [4 +
Process for the preparation of bicycloheptane derivatives, and novel bicycloheptane derivatives
申请人:SHELL INTERNATIONALE RESEARCH
MAATSCHAPPIJ B.V.
公开号:EP0081892A2
公开(公告)日:1983-06-22
A process for the preparation of a 2-exo-hydroxy-7-oxa- bicyclo[2.2.1]heptane, wherein the corresponding cis 3,4-expoxycyclohexanol is cyclised by treatment with an acid. Specific 2-exo-hydroxy-7-oxabicyclo[2.2.1]heptanes and intermediates thereof.
A study of epoxyolefin cyclizations catalyzed by bismuth trifluoromethanesulfonate and other metal triflates
作者:Joshua R. Lacey、Peter W. Anzalone、Christopher M. Duncan、Matthew J. Hackert、Ram S. Mohan
DOI:10.1016/j.tetlet.2005.10.013
日期:2005.12
Epoxyolefin cyclizations have attracted considerable interest due to their importance in biosynthetic pathways. Bismuth trifluoromethanesulfonate as well as several other metal triflates are shown to be highly effective (0.1 mol %) catalysts for the cyclization of geraniolene oxide. The product composition is found to be more dependent on solvent and substrate concentration than on the nature of the metal triflate. Cyclization products are favored in CH2Cl2 and under high dilution conditions. Ether solvents favored acyclic products. (c) 2005 Elsevier Ltd. All rights reserved.
Demonstration of a Common Concerted Mechanistic Pathway for the Acid-Catalyzed Cyclization of 5,6-Unsaturated Oxiranes in Chemical and Enzymatic Systems