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Regioselective Fries Rearrangement and Friedel−Crafts Acylation as Efficient Routes to Novel Enantiomerically Enriched ortho ‐Acylhydroxy[2.2]paracyclophanes
Author(s) -
Rozenberg Valeria,
Danilova Tat’yana,
Sergeeva Elena,
Vorontsov Evgenii,
Starikova Zoya,
Lysenko Konstantin,
Belokon’ Yuri
Publication year - 2000
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 - 10.1002/1099-0690(200010)2000:19<3295::aid-ejoc3295>3.0.co;2-0
Subject(s) - fries rearrangement , regioselectivity , chemistry , friedel–crafts reaction , acylation , enantiomer , cyclophane , stereochemistry , organic chemistry , catalysis , molecule
Two useful approaches to ortho ‐acylhydroxy[2.2]paracyclophanes, starting from 4‐hydroxy[2.2]paracyclophane, have been developed. TiCl 4 ‐catalyzed Fries rearrangement and direct acylation occur regioselectively (to the ortho position with respect to the hydroxy group), leading to 4‐acetyl‐5‐hydroxy[2.2]paracyclophane ( 3 ) and 4‐benzoyl‐5‐hydroxy[2.2]paracyclophane ( 4 ) in high to excellent chemical yields. For compound 4 , an X‐ray investigation has been performed. ortho ‐Acylhydroxy[2.2]paracyclophanes 3 and 4 have been obtained in enantiomerically enriched forms ( ee 92−99%) and the absolute configurations of their enantiomers have been determined.