Premium
Regioselective Olefination of Cross‐Conjugated 3‐Thioxosteroids by [3+2] Cycloaddition
Author(s) -
Fiedler Beate,
Weiß Dieter,
Beckert Rainer
Publication year - 1997
Publication title -
liebigs annalen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0947-3440
DOI - 10.1002/jlac.199719970324
Subject(s) - chemistry , regioselectivity , diazo , cycloaddition , conjugated system , sulfur , nitrogen , medicinal chemistry , ring (chemistry) , organic chemistry , stereochemistry , catalysis , polymer
Reaction of 3‐thioxoandrosta‐1,4‐dien‐17‐one ( 1 ) with the diazo compounds 2a–i affords 4′‐substituted spiro[17‐oxoandrosta‐1,4‐diene‐3,2′‐[1,3,4]thiadiazolines], which undergo a two‐step ring contraction with extrusion of nitrogen and sulfur, leading to the substituted 3‐methylen‐ and 3‐propylidenandrosta‐1,4‐dien‐17‐ones 3a–i in good yields.