Ethylbenzene Hydroperoxide: An efficient oxidizing agent for diastereoselective synthesis of Spiroepoxy oxindoles
作者:Praveen K. Valmiki、Mohan Banyangala、Sunil Varughese、Sasidhar B. Somappa
DOI:10.1016/j.tetlet.2022.154126
日期:2022.10
Ethylbenzene hydroperoxide (EBHP) has been studied for the epoxidation of oxindole chalcones with various inorganic bases and different solvent systems. 10 M solution of NaOH with EBHP in hexane furnished a high yield of spiro epoxy oxindoles in a short reaction time at room temperature. The reaction condition applicable to electron-deficient, electron-rich arylideneindolin-2-ones, heteroarylideneindolin-2-ones
已经研究了乙苯过氧化氢 (EBHP) 用于各种无机碱和不同溶剂体系对羟吲哚查耳酮的环氧化反应。10 M NaOH 与 EBHP 在己烷中的溶液在室温下的短反应时间内提供了高产率的螺环环氧羟吲哚。该反应条件适用于缺电子、富电子的亚芳基二氢吲哚-2-酮、杂亚芳基二氢吲哚-2-酮和亚烷基二氢吲哚-2-酮,得到非对映选择性芳基/杂芳基和烷基螺环氧乙烷。过氧化物试剂中的比较研究表明,EBHP 在非对映选择性、产率和反应时间方面是最好的。同位素标记实验表明水分子参与了这种氧化机制。
Biocatalysis: fungi mediated novel and selective 12β- or 17β-hydroxylation on the basic limonoid skeleton
作者:Saikat Haldar、Swati P. Kolet、Hirekodathakallu V. Thulasiram
DOI:10.1039/c3gc40193f
日期:——
Basic limonoids carrying a 4,4,8-trimethyl-17-furanylsteroid skeleton are a class of triterpenoids and well-known for their insecticidal as well as a vast array of pharmacological activities. Rare and synthetically challenging 12β- and 17β-hydroxylation was achieved on the basic limonoid skeleton to produce a novel series of hydroxylated limonoids using fungi-mediated biocatalysis. The fungal system belonging to the genera of Mucor efficiently converted azadiradione, epoxyazadiradione, gedunin and their derivatives into corresponding 12β- and/or 17β-hydroxy derivatives. The position and stereochemistry of hydroxylation was determined by rigorous spectroscopic and crystallographic studies. This fungi-mediated stereo- and regio-selective hydroxylation process was highly efficient and mild enough to sustain chemically sensitive functional groups around the basic limonoid skeleton. Modifications of specific functional groups and variation in biocatalyst were shown to bring selectivity among 12β- or 17β-hydroxylation.
Transformation of Azadiradione to Nimbocinol and 17β-Hydroxynimbocinol, and StructurePesticidal-Activity Relationship of Triterpenoids isolated fromAzadirachta indica A. Juss. (Neem)
作者:Bina S. Siddiqui、Munawwer Rasheed、Shaheen Faizi、Firdous、S. Tariq Ali、Rajput M. Tariq、Syed Naeem-ul-Hassan Naqvi
DOI:10.1002/hlca.200390277
日期:2003.10
During studies on the structurepesticidal-activity relationship of Azadirachta indica constituents, azadiradione (1) was treated with methanolic K2CO3 to obtain 7-deacetyl derivative nimbocinol (2). Unexpectedly, 17β-hydroxynimbocinol (3), reported earlier as a natural product, was also formed. The structurepesticidal-activity relationship of triterpenoids 1–16 against Anopheles stephensi Liston is described
期间的structurepesticidal -活性关系研究印楝成分,azadiradione(1)中的溶液用甲醇K处理2 CO 3,得到7-脱乙酰衍生物nimbocinol(2)。出乎意料的是,还形成了17β-羟基苯丁二酚(3),较早时被报道为天然产物。三萜类化合物1 – 16对斯蒂芬按蚊的结构杀虫活性关系描述Liston旨在理解负责具有阿朴双烯(apotirucallaneane)和gedunin skeleta的三萜类化合物的杀虫活性的活性功能。三萜类化合物的杀虫活性2 - 8报告首次。
7-Deacetyl-17β-hydroxyazadiradione, a new limonoid insect growth inhibitor from Azadirachta indica
作者:S.Mark Lee、Jay I. Olsen、Martin P. Schweizer、James A. Klocke
DOI:10.1016/0031-9422(88)80661-7
日期:1988.1
tetranortriterpenoid of the limonoid type, 7-deacetyl-17β-hydroxyazadiradione, and the known compound azadiradione, were isolated from the seeds of Azadirachta indica . The structure of the new compound was established by spectroscopic methods. The activity of the new compound as an insectgrowthinhibitor against Heliothis virescens was found to be greater than that of azadiradione and 7-deacetylazadiradione.