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Unusual Rearrangements of cis ‐4,7‐Disubstituted 4,7‐Dihydro4,7‐dihydroxy[2.2]paracyclophanes on Dehydration: Stereoselective Formation of Planar Chiral Cyclohexadienones
Author(s) -
Vorontsova Natalia,
Rozenberg Valeria,
Vorontsov Evgenii,
Antonov Dmitrii,
Starikova Zoya
Publication year - 2003
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200390119
Subject(s) - chemistry , substituent , dehydration , stereoselectivity , alkyl , stereochemistry , quinone , medicinal chemistry , phenols , organic chemistry , catalysis , biochemistry
Under acid conditions, cis ‐4,7‐disubstituted 4,7‐dihydro‐4,7‐dihydroxy[2.2]paracyclophanes undergo dehydration accompanied by rearrangement, affording cyclohexadienone derivatives as major products and with polysubstituted phenols being formed as minor products. The formation of either an ortho or a para semiquinoid system, as well as the configuration of the newly formed asymmetric center, depended strictly on the nature of the substituent (alkyl, allyl, or phenyl). The structures of 3,4‐dihydro‐3,7‐dimethyl[2.2]paracyclophane‐4‐one ( 10 ), 3,7‐diallyl‐3,4‐dihydro[2.2]paracyclophane‐4‐one ( 12 ), and 4,7‐dihydro‐7,8‐diphenyl[2.2]paracyclophane‐4‐one ( 22 ) were determined by X‐ray structural analysis. [2.2]Paracyclophane‐4,7‐quinone ( 1 ) was obtained in optically active form. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)