Methyl(bismethylthio)sulphonium hexachloroantimonate (1a) reacts under mild conditions with 2-allylphenol (3a) to give 2-(methylthiomethyl)-2,3-dihydrobenzofuran (4a). Methylthiolation at position 5 in the heterocycle may also occur. With 4-substituted 2-allylphenols (3b–d)(substituents: methyl,chloro,nitro) only the corresponding 5-substituted 2-(methylthiomethyl)-2,3-dihydrobenzofurans (4b–d) are
The complete and irreversible conversion of a cis carbon-substituted thiiranium ion into the trans isomer
作者:Lucia Pasquato、Giorgio Modena
DOI:10.1039/a902221j
日期:——
t-2-tert-Butyl-t-3-phenyl-r-1-methylthiiranium 1 isomerizes into the more stable (32.3 kJ mol–1) t-2-tert-butyl-c-3-phenyl-r-1-methylthiiranium 2 in a complete and irreversible process (monitored by proton NMR at –30 °C) via an open benzylic carbenium ion.