ISSN:
0021-8383
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
10β;-Chloro-estra-1,4-dienes as Intermediates of the Introduction of a 9(11)-Double Bond in Estra-1,3,5(10)-trienesThe synthesis of 9(11)-didehydro-estra-1,3,5(10)-trienes 5 starting from estra-1,3,5(10)-trienes 1 is described. 1 can be transformed into the ketals 2 and 3 by means of isocyanuric acid chloride and an alcohol such as methanol or ethylene glycol in the absence of moisture.The ketals 2 and 3 are sensitive against hydrolysis and react in the presence of water and traces of acid under formation of chlorodienone 4. Dehydrochlorination of 2, 3 and 4 with potassium-tert.-butylate in dimethylsulfoxide gives the 9(11)-didehydro compounds 5. The reaction mechanism of the electrophilic addition of positive chlorine and alcohol to the aromatic A-ring of 1 is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prac.19843260612
