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)。
Synthesis of Paclitaxel. 1. Synthesis of the ABC Ring of Paclitaxel by SmI2-Mediated Cyclization
摘要:
A convergent synthesis of the ABC ring of antitumor natural product paclitaxel (Taxol) is described. SmI2-mediated reductive cyclization of an allylic benzoate possessing an aldehyde function, synthesized from tri-O-acetyl-D-glucal and 1,3-cyclohexanedione, smoothly afforded the highly strained 6-8-6 tricarbocyclic Structure in 66% yield.
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.
Compounds of the formula ##STR1## wherein X is (--CR.sub.4 R.sub.4 --).sub.m in which m is 0 or 1; Y is (--CR.sub.5 R.sub.6 --).sub.n in which n is 0, 1 or 2; Z is (--CR.sub.7 R.sub.7 --).sub.p in which p is 1, 2, or 3; the sum of m+n+p is an integer of 2 to 5, inclusive; R.sub.2 and R.sub.3 each is H or alkyl, and the like; R.sub.1 is H or alkyl; and W is an unsaturated moiety, are useful as plant growth regulators and herbicides.
Certain substituted, 7-oxabicyclo[2.2.1]heptan-2-ols and -2-ones as
申请人:Shell Oil Company
公开号:US04554366A1
公开(公告)日:1985-11-19
Compounds of the formula ##STR1## wherein X is (--CR.sub.4 R.sub.4 --).sub.m in which m is 0 or 1; Y is (--CR.sub.5 R.sub.6 --).sub.n in which n is 0, 1 or 2; Z is (--CR.sub.7 R.sub.7 --).sub.p in which p is 1, 2 or 3; the sum of m+n+p is an integer of 2 to 5, inclusive; R.sub.2 and R.sub.3 each is H or alkyl, and the like; R.sub.1 is H or alkyl; and W is an unsaturated moiety, are useful as plant growth regulators and herbicides. Novel intermediates are also disclosed.
Compounds of the formula ##STR1## wherein X is (--CR.sub.4 R.sub.4 --).sub.m in which m is 0 or 1; Y is (--CR.sub.5 R.sub.6 --).sub.n in which n is 0, 1 or 2; Z is (--CR.sub.7 R.sub.7 --).sub.p in which p is 1, 2 or 3; the sum of m+n+p is an integer of 2 to 5, inclusive; R.sub.2 and R.sub.3 each is H or alkyl, and the like; R.sub.1 is H or alkyl; and W is an unsaturated moiety, are useful as plant growth regulators and herbicides.
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.