A facile and efficient ZrCl 4 catalyzed conversion of aldehydes to geminal-diacetates and dipivalates and their cleavage
摘要:
A novel, mild and efficient method has been developed for the preparation of geminal-diacetates and dipivalates in high yields through a reaction of aldehydes with acetic anhydride or pivalic anhydride using Zirconium (W) chloride as a catalyst under solvent free conditions. Regeneration of aldehydes from the acylals was also achieved using the same catalyst in CH3OH. (C) 2003 Elsevier Ltd. All rights reserved.
HBF 4 -SiO 2 has been found to be an outstanding catalyst for the protection of carbonyl compounds as acylals under entirely solvent-free conditions. Some of the major advantages of this procedure are high yields, ease of operation, high chemoselectivity, high atom efficiency, and compatibility with other protecting groups.