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Carbonium cyclization—studies on lignans containing the dibenzocyclooctadiene system, II
Author(s) -
Tan Rui,
Liang XiaoTian
Publication year - 1991
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.19910090315
Subject(s) - chemistry , thionyl chloride , carbonium ion , ritter reaction , pyridine , ring (chemistry) , medicinal chemistry , chloride , organic chemistry , catalysis
Abstract Studies of schisandrol B under Ritter reaction conditions showed similar results to that of schisandrin. However the carbonium cyclization product (4a) of schisandrol B undergoes oxidative ring opening when exposed to the air. Cyclization of schisantherin A (2) also occurs by treatment with thionyl chloride in pyridine. Here the presence of the extra benzoyloxy group somehow confers stability to the diosphenol system and 8 has to be stirred in solution under oxygen for extended periods to effect ring opening.