Total synthesis of androstanes

1979 ◽  
Vol 57 (24) ◽  
pp. 3356-3358 ◽  
Author(s):  
Masatoshi Kakushima ◽  
Jagabandhu Das ◽  
Gary R. Reid ◽  
Peter S. White ◽  
Zdenek Valenta

A total synthesis of androstane derivatives is described. The desired configuration at C8 and at C13 is achieved in a ring C forming SnCl4-catalyzed Diels–Alder reaction. The preparation of methyl Z-2-methyl-4-oxo-2-pentenoate and the cyclization of a keto ester to a steroid 15,17-dione are also reported.


1993 ◽  
Vol 71 (9) ◽  
pp. 1484-1494 ◽  
Author(s):  
Edward Piers ◽  
Montse Llinas-Brunet ◽  
Renata M. Oballa

A total synthesis of the structurally novel, antimicrobial diterpenoid (±)-8,15-diisocyano-11(20)-amphilectene (2) is described. Alkylation of 2-methoxycarbonyl-3-methylcyclohexanone (13) with (E)-1-(tert-butyldimethylsiloxy)-6-iodo-3-(trimethylstannyl)-2-hexene (14) provided, stereoselectively, the functionalized keto ester 15, which was converted efficiently into the diene 17. Diels–Alder reaction of 17 with acrolein, followed by base-catalyzed equilibration of the resultant product mixture, gave the aldehydes 19 (58%) and 20 (29%). Allylic oxidation of the alkene 24 (derived from 19) afforded the enone 25. Reduction (Na, NH3, t-BuOH) of 25 gave 28, which was converted, via a sequence of eight synthetic steps, into the diacid 45. Efficient transformation of the carboxyl functions of 45 into isonitrile groups completed the synthesis of (±)-2.







2017 ◽  
Vol 19 (3) ◽  
pp. 429-431 ◽  
Author(s):  
Tian-Ze Li ◽  
Chang-An Geng ◽  
Xiu-Juan Yin ◽  
Tong-Hua Yang ◽  
Xing-Long Chen ◽  
...  


1980 ◽  
Vol 102 (22) ◽  
pp. 6893-6894 ◽  
Author(s):  
William G. Dauben ◽  
Carl R. Kessel ◽  
Kazuo H. Takemura


1979 ◽  
Vol 57 (24) ◽  
pp. 3354-3356 ◽  
Author(s):  
Masatoshi Kakushima ◽  
Leonard Allain ◽  
Robert A. Dickinson ◽  
Peter S. White ◽  
Zdenek Valenta

A total synthesis of (±)-5β,8α- androst-9(11)-ene-3,17-dione is described. The key step is a ring C forming SnCl4-catalyzed Diels–Alder reaction in which the geometry of the diene controls syn–anti stereochemistry while the catalyst guides the addition to the desired endo orientation. A preparation of ethyl E-2-methyl-4-oxo-2-butenoate and the dehydration of a tertiary allylic alcohol by the pyrolysis of the corresponding tosyl carbamate are also described.





1996 ◽  
pp. 225-226 ◽  
Author(s):  
Goh Matsuo ◽  
Yuko Miki ◽  
Masaya Nakata ◽  
Shuichi Matsumura ◽  
Kazunobu Toshima


2008 ◽  
Vol 120 (7) ◽  
pp. 1328-1331 ◽  
Author(s):  
Zhipeng Yu ◽  
Xiaohua Liu ◽  
Zhenhua Dong ◽  
Mingsheng Xie ◽  
Xiaoming Feng


Sign in / Sign up

Export Citation Format

Share Document