The Claisen rearrangement of 3-oxy-2-allyloxyindoles through base-induced enolization of 2-allyloxyindolin-3-ones was investigated. This rearrangement reaction proceeded smoothly at low temperature and showed intriguing diastereoselectivity that did not depend on the initial olefin geometry.
A robust and rapid synthesis of 3-hydroxy-3-alkyl-2-oxindoles from isatins is described. This method introduces an ecofriendly, un-activated Zn dust, solid $$\hbox NH}_4}\hbox Cl}$$ and substrates under aqueous conditions, which has produced the product in moderate to good yields. Without using column chromatography, majority of the compounds were isolated in analytically pure form. The progress of the reaction could be visualized by naked eye. SYNOPSIS A robust and rapid synthesis of 3-hydroxy-3-alkyl-2-oxindoles from isatins is described. This method introduces an ecofriendly method using un-activated Zn dust, solid $$\hbox NH}_4}\hbox Cl}$$ and substrates under aqueous conditions, which has produced the products in moderate to good yields.