Journal of Organic Chemistry p. 3098 - 3108 (1986)
Update date:2022-08-02
Topics:
Baggiolini, Enrico G.
Iacobelli, Jerome A.
Hennessy, Bernard M.
Batcho, Andrew D.
Sereno, John F.
Uskokovic, Milan R.
1α,25-dihydroxycholecalciferol (4) and 1α,25-dihydroxyergocalciferol (7), the hormonally active forms of vitamin D3 (1) and vitamin D2 (5), were synthesized by a Horner-Wittig reaction of the phosphine oxide 11 with the ketones 10 and 12, respectively.The synthon 11 was obtained by a sequence that involves the stereospecific opening of epoxide 15, with sodium acetate in acetic acid, followed by oxidative degradation of the isopropenyl side chain and dehydration of the intermediate 22.Photoisomerisation of the resulting 23 gave 24, which was finally converted to 11.The hydroxylated ketone 10 was obtained from the known intermediate 28.The introduction of the 25-hydroxy side chain was achieved by reaction of the lithium derivative of 30 with the tosylate 29 to give 31, which was catalytically hydrogenated to 32 and then converted to 10.The ketone 12 was prepared by a stereocontrolled route that involves as the key step, the <3+2> dipolar cycloaddition of nitrone 35 with methyl 3,3-dimethylacrylate (36) to give a 1:1 mixture of isoxazolidines 37 and 38.Stereochemical control was achieved by taking advantage of the thermal reversibility of the cycloaddition, which allows the reequilibration of undesired 37.Isoxazolidine 38 was readily transformed to 43 by reduction, followed by elimination of the nitrogen function, and finally oxidation to 12.
View MoreHunan Zhongqi Pharmaceutical Co., Ltd
website:http://www.hnzqzy.com
Contact:0730-8722288 13807308622
Address:Wanjiafan Road ,Yueyang Economic And Technological Development Zone ,Hunan,PRC
Wuhan Fortuna Chemical Co.,Ltd
website:http://www.fortunachem.com
Contact:86-27-59207850
Address:Add: Room 2015, No.2 Building, Kaixin Mansion No.107 Jinqiao Avenue, Wuhan, China
Yicheng Goto Pharmaceuticals Co.,Ltd.
Contact:+86 710 3423122
Address:5th Floor,East Gate of Building #2,Servo-Industrial Park,1st Qilin Road,Xiangyang,Hubei,China
LIAOYANG WANRONG CHEMICALS COMPANY LIMITED
Contact:86-419-2390789
Address:XINLI VILLAGE , DONG NINGWEI COUNTY,TAIZIHE DISTRICT, LIAOYANG , LIAONING
Zhejiang Tianyu Pharmaceutical Co., Ltd.
Contact:+86-576-84177669, 89189665,89189688,84168770
Address:Jiangkou Development Zone, Huangyan, Taizhou City, Zhejiang
Doi:10.1021/jo00210a041
(1985)Doi:10.1039/DT9840002859
()Doi:10.1021/ic701201x
(2007)Doi:10.1021/jo7018587
(2007)Doi:10.1515/znb-1984-1125
(1984)Doi:10.1016/S0040-4020(01)91497-8
(1984)