Intramolecular hydrogen abstraction. The use of organoselenium reagents for the generation of alkoxy radicals
作者:R.L Dorta、C.G Francisco、R Freire、E Suárez
DOI:10.1016/s0040-4039(00)82887-7
日期:——
The alkoxy radical intermediates, produced by photolysis of several hydroxy compounds in the presence of diphenylselenuranes (1) and iodine, undergo intramolecularhydrogenabstraction to afford cyclic ethers in good yield.
Oxidative Entry into the <i>Illicium</i> Sesquiterpenes: Enantiospecific Synthesis of (+)-Pseudoanisatin
作者:Kevin Hung、Matthew L. Condakes、Takahiro Morikawa、Thomas J. Maimone
DOI:10.1021/jacs.6b11739
日期:2016.12.28
sesquiterpenes have been the subject of numerous synthetic efforts due to their ornate and highly oxidized structures as well as significant biological activities. Herein we report the first chemical synthesis of (+)-pseudoanisatin from the abundant feedstock chemical cedrol (∼$50 USD/kg) in 12 steps using extensive site-selective C(sp3)-H bond functionalization. Significantly, this work represents a novel
Facile Construction of the Tricyclo[5.2.1.0<sup>1,5</sup>]decane Ring System by Intramolecular Double Michael Reaction: Highly Stereocontrolled Total Synthesis of (±)-8,14-Cedranediol and (±)-8,14-Cedranoxide
作者:Masataka Ihara、Kei Makita、Kiyosei Takasu
DOI:10.1021/jo981996n
日期:1999.2.1
It was observed that the synthesis of tricyclo[5.2.1.0(1,5)]decane 10 can be performed effectively by the intramolecular double Michael reaction of 5-(5-methoxycarbonyl-4-pentenyl)-2-cyclopenten-1-one (9). Highly stereocontrolled total syntheses of(+/-)-8, 14-cedranediol (2) and (+/-)-8,14-cedranoxide (1) were accomplished by the application of this methodology. Heating 5-(1,5-dimethyl-5-ethoxycarbonylpent-4-enyl)-2-cyclopenten-1-one (15) with TMSCl, Et3N, and ZnCI2 in o-dichlorobenzene at 150 degrees C provided (+/-)-(1R*, 2R*, 5R*, 6R*, 7S*)-2,6-dimethyl-6-ethoxycarbonyltricyclo[5.2.1.0(1,5)]- decan-9-one (16) as a single isomer. The product 16 was stereoselectively converted into the above cedranoids 2 and 1 through ring expansion chemistry.