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Sterically Hindered Carbonyl O ‐Oxides and Dioxiranes − (6‐ tert ‐Butyl‐2,3,4‐trimethylphenyl)phenylcarbonyl O ‐Oxide and (6‐ tert ‐Butyl‐2,3,4‐trimethylphenyl)phenyldioxirane
Author(s) -
Schroeder Kerstin,
Sander Wolfram
Publication year - 2005
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.200400437
Subject(s) - chemistry , dioxirane , ketone , steric effects , medicinal chemistry , oxide , organic chemistry , nuclear chemistry
(6‐ tert ‐Butyl‐2,3,4‐trimethylphenyl)phenylcarbonyl O ‐oxide ( 1b ) was generated by photooxidation of diazo compound 6b in an organic glass and in solution and characterized by UV/Vis spectroscopy and by its photo‐ and thermochemistry. With 4.5 min at 230 K the half‐life of 1b is considerably smaller than that of dimesityl ketone O ‐oxide ( 1a ). The only clearly detected thermal product of 1b is the corresponding ketone 3b . The isomeric (6‐ tert ‐butyl‐2,3,4‐trimethylphenyl)phenyldioxirane ( 2b ) could also be synthesized and characterized by NMR spectroscopy. With a half‐life time of 20 min at 20 °C this dioxirane rearranges to the isochroman derivative 11 as the only product. Plausible mechanisms for this rearrangement, which involves the hydroxylation of a non‐activated C−H bond, are discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)