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Inter‐ and Intramolecular Hetero Diels‐Alder Reactions, 31. Synthesis of D‐Homoestrone Derivatives by Tandem Knoevenagel Hetero Diels‐Alder Reactions from Natural Estrone
Author(s) -
Tietze Lutz F.,
Wölfling János,
Schneider Gyula
Publication year - 1991
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19911240327
Subject(s) - chemistry , knoevenagel condensation , diels–alder reaction , intramolecular force , tandem , adduct , cascade reaction , cycloaddition , diastereomer , yield (engineering) , medicinal chemistry , stereochemistry , organic chemistry , catalysis , materials science , metallurgy , composite material
Abstract The tandem Knoevenagel hetero Diels‐Alder reaction of the secoestrone derivative 8 with dimethylbarbituric acid ( 9a ). Meldrum's acid ( 9b ), and the pyrazolones 13a – c stereoselectively affords the D‐homoestrone derivatives 11a, 12 , and 14a – c , respectively, with the 16α,17aα configuration in excellent yield. In the reaction of 8 with 9a, b only one diastereomer can be detected, whereas in the reaction of 8 with 13a – c a small amount of the isomeric adducts 15a – c has also been found.