Helvetica Chimica Acta p. 1361 - 1378 (1996)
Update date:2022-07-30
Topics:
Stahl
Borschberg
Acklin
The methanolysis of the epimeric 7-chloro-7H-yohimbine derivatives 2 and 3 was reinvestigated. In case of the 7α-epimer 2, the reaction was uneventful and conformed with earlier observations, i.e., under sufficiently mild conditions, only the imino ether 4 (= imino ether A) was produced. Under the same conditions, the less reactive β-isomer 3 furnished a mixture of both imino ethers 4 and 5, accompanied by the elimination product 11, and by equal amounts of yohimbine (1) and 3,4,5,6-tetradehydroyohimbine (12), which are believed to arise through a disproportionation process of the putative intermediate 5,6-didehydroyohimbine (23). The nature of this divergent reactivity and of the ready equilibration of 4 and 5 was investigated by means of extensive force-field and semi-empirical calculations (AM1 and PM3) of various conformers of the compounds 2-5 and of some possible reaction intermediates.
View MoreShanghai Pinewood Fine Chemical Co., Ltd.
website:http://www.pinewoodchem.com
Contact:0086-21-62417129,62414096
Address:Suite B, 27F, No.2, Lane 600, Tianshan Road, Shanghai
Shanghai Zhihua ChemTech Co., Ltd.
Contact:+86-13774313779
Address:Room 817 Suite B 3333 Shenjiang Road
Shanghai united Scientific Co.,Ltd.
Contact:+86-21-53535353
Address:28F No.900 huaihai Road Shanghai China
Chengdu Cogon Bio-tech Co., Ltd.
Contact:86-28-85171192
Address:NO.52.YongFeng Rd. Chengdu,610041,P.R.China.
Hebei Tianxiang Biological & Pharmaceutical Co., Ltd
Contact:86-0312-6615158
Address:No 42 fazhan street qingyuan county
Doi:10.1039/c7md00199a
(2017)Doi:10.1002/jlcr.2580160202
(1979)Doi:10.1002/jlcr.2580340406
(1994)Doi:10.1055/s-0031-1291161
(2012)Doi:10.1021/jm00176a006
(1980)Doi:10.1021/ja031587v
(2004)