A novel regioselective synthesis of a number of functionalized 3-spiropyrrolizidine and 3-spiropyrrolidine oxindoles from Baylis-Hillman adducts of isatin and heteroaldehydes via [3+2] cycloaddition of azomethine ylides in excellent yields has been reported.

An activation of the pyridine nucleus has been achieved via 1,5-electrocyclization of vinyl pyridinium ylides generated from bromo isomerized Morita-Baylis-Hillman adducts of isatin and pyridine under basic conditions. The method has been successfully applied for an efficient synthesis of a number of 3-spirodihydroindolizine-2-oxindoles, which have been found as core structure of secoyohimbane and heteroyohimbane alkaloid natural products.

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-035Facile Reduction of Carboxylic Acids by Zinc Borohydride.The ready conversion of aliphatic and aromatic carboxylic acids to alcohols by Zn(BH4)2 with good selectivity and concomitant hydroboration of unsaturated acids to the corresponding diols by Zn( BH4)2 should be a valuable method for application in synthetic organic chemistry.