Regioselective synthesis of 3-(methylthio)phenols by formal [3+3]-cyclocondensations of 3-oxo-bis(methylthio)ketenacetals with 1,3-bis(trimethylsilyloxy)-1,3-butadienes and 1,3-dicarbonyl dianions
The cyclization of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 3-oxo-bis(methylthio)ketenacetals afforded 3-(methylthio)phenols containing an acyl or ester substituent located at position 2. The cyclization of free 1,3-dicarbonyl dianions with 3-oxo-bis(methylthio)ketenacetals resulted in the formation of regioisomeric products containing an acyl group located at position 6.
Novel cycloaromatization in reformatsky reaction on ∝-oxoketene dithioacetals: A regioselective synthesis of substituted ethyl 2-hydroxy-6-methylthiobenzoates
A novel cycloaromatization reaction leading to substituted ethyl 2-hydroxy-3-methylthiobenzoates by condensation ∝-oxoketene dithioacetals with excess of Reformatsky reagent from ethyl bromoacetate through intermediate dienes 3 has been reported.
Reformatskii reaction on .alpha.-oxo ketene dithioacetals: synthesis of substituted and fused ethyl 2-hydroxy-6-(methylthio)benzoates, 6-(methylthio)pyran-2-ones, and 6-(methylthio)-2(1H)pyridone derivatives