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The Diels‐Alder Reaction of Dienes Derived from Substituted 3‐(Phenyl‐Thio)‐3‐Sulfolenes
Author(s) -
Chou ShangShing P.,
Liou ShyYeon,
Tsai ChungYing
Publication year - 1988
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.198800056
Subject(s) - chemistry , cycloaddition , methyl vinyl ketone , regioselectivity , methyl acrylate , ketone , stereoselectivity , medicinal chemistry , stereospecificity , organic chemistry , thio , diels–alder reaction , monomer , catalysis , polymer
Substituted 3‐(phenylthio)‐3‐sulfolenes (3) and (4) are good precursors for 2‐(phenylthio)‐1,3‐butadienes (5) and (6). The Diels‐Alder reaction of the dienes derived from (3) and (4) with various dienophiles was studied. It was found that heating of sulfolenes (3) with methyl propiolate and N‐phenylmaleimide afforded the Diels‐Alder adducts of (5) directly and with complete regio‐ and stereospecificity. The same reaction with methyl vinyl ketone gave a mixture of endo and exo addition products. If sulfolenes (3) were first converted to the dienes (5) using lithium aluminum hydride and then reacted with methyl vinyl ketone in the presence of anhydrous zinc chloride, the stereoselectivity could be improved. Sulfolenes (4) also underwent cycloreversion/cycloaddition with methyl acrylate, methyl vinyl ketone, and N‐phenylmaleimide, but gave mostly the double bond‐isomerized cycloaddition products. The regiochemistry of cycloaddition was delicately dependent on the dienophiles used.