Journal of Organic Chemistry p. 5785 - 5789 (1995)
Update date:2022-08-04
Topics:
Shing, Tony K. M.
Yang, Jun
The absolute configuration on naturally occurring oblongolide is confirmed as (3aS,5aR,7S,9aS,9bS)-3a,5a,6,7,8,9,9a,9b-octahydro-7,9b-dimethylnaphtho<1,2-c>furan-1(3H)-one (1) on the basis of a six-stage or an eight-stage synthesis from (-)-citronellol involving a steric-controlled, regioselective reduction and an intramolecular Diels-Alder (IMDA) reaction or a transannular Diels-Alder (TDA) reaction as the key steps. (-)-Citronellol (5) was converted into methyl (2E,4E,10E)-(S)-(+)-11-(tert-butoxycarbonyl)-7-methylundeca-2,4,10-trienoate (7) by sequential Lemiuex-Johnson oxidation, Wittig olefination, pyridinium dichromate oxidation, and Wadsworth-Emmons-Horner alkenation.A regioselective reduction of the methoxycarbonyl group in 7 afforded tert-butyl (2E,8E,10E)-(S)-(+)-2,6-dimethyl-12-hydroxydodeca-2,8,10-trienoate (8) from which oblongolide (1) was obtained via an IMDA reaction.The macrocyclic (2E,8E,10E)-(S)-(+)-2,6-dimethyldodeca-2,8,10-trieno-1,12-lactone derived from 8 underwent a highly stereoselective TDA reaction to give 1 at a lower reaction temperature, in a shorter reaction time and in a better yield than the analogous IMDA reaction.
View MoreXinjiang Zhongtai Chemical Co., Ltd.
Contact:+86-991-8788172
Address:NO.78 XISHAN RD.URUMQI,CHINA
Rudong Zhenfeng Yiyang Chemical Co., Ltd.
Contact:0513-84573047
Address:South Fengli Town, Rudong County, Jiangsu Province, China
Suzhou SuKaiLu Chemical Technology Co., Ltd.
Contact:+86-512-62766020
Address:Floor 4, Building 1, Xinyi Pharmaceutical Valley Wisdom Industrial Park, 415 Changyang Street, Suzhou Industrial Park, Jiangsu Province
Guangzhou Reachin Chemical Co., Ltd
Contact:+86-20-37087379 ext.604
Address:A122C-1, Tianyuan Plaza, 401 Tianyuan Rd., Tianhe, Guangzhou, China
Ningbo Distant Chemicals Co.,Ltd
Contact:86-574-27862490,27862438
Address:5F-3,#54 DaShaNi street,Ningbo,CHINA
Doi:10.1002/ardp.19753080704
(1975)Doi:10.1021/jo00865a006
(1976)Doi:10.1021/acs.orglett.6b02981
(2016)Doi:10.1021/ol034428p
(2003)Doi:10.1080/10426509808045488
(1998)Doi:10.1039/a704024e
(1997)