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Epoxidation of 2,3‐Dimethylbenzofurans by Dimethyldioxirane
Author(s) -
Adam Waldemar,
Bialas Joachim,
Hadjiarapoglou Lazaros,
Sauter Markus
Publication year - 1992
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19921250136
Subject(s) - chemistry , epoxide , dimethyldioxirane , isomerization , tautomer , adduct , dioxirane , methanol , organic chemistry , medicinal chemistry , photochemistry , catalysis
The synthesis of epoxides 2 by the reaction of the chloro‐ and methyl‐substituted 2,3‐dimethylbenzofurans 1 with dimethyl‐dioxirane at low temperature is reported. These labile epoxides were spectroscopically characterized ( 1 H and 13 C NMR) at subambient temperatures. Epoxidation of benzofuran 1c affords a 31:69 mixture of epoxide 2c and quinone methide 3c , the latter presumably being produced by valence isomerization of the epoxide. On warming up above −10°C, the epoxides 2 suffer decomposition. Treatment of epoxide 21 with methanol yields the tautomeric mixture of adducts 4i and 4i ′.