Reduction of aromatic and aliphatic keto esters using sodium borohydride/MeOH at room temperature: a thorough investigation

Reduction of keto esters is a valuable alternative to produce diols. Sodium borohydride/MeOH system at room temperature and short reaction time efficiently reduced alpha, beta, gamma, and delta-keto esters having alpha-keto esters as the most reactive. The ester functionality was reduced effectively due to the presence of oxo group that somehow facilitates the formation of ring intermediate. As expected, the chemoselective experiments showed that ester functionality was not reduced using this system. This study presents a simple, easy, and benign reduction process of various keto esters to its corresponding diols. (C) 2010 Elsevier Ltd. All rights reserved.J.K., K.A.D.C., and M.L. acknowledge financial support from the Korean Ministry of Education through the 2nd stage of the BK21 project for the Hanyang University graduate program and M.L. also acknowledges Seoul Metropolitan Government for Seoul Science Fellowship