A selective ring opening reaction of 4,6-O-benzylidene acetals in carbohydrates using trialkylsilane derivatives

Reductive ring opening reactions of 4,6-O-benzylidene-protected carbohydrates to the corresponding benzyl ethers using trialkylsilane derivatives were examined. When Et3SiH(or PS-DESTM)-TfOH was used, 6-O-benzyl ethers with 4-hydroxy unsubstituted were obtained, while, when Et3SiH(or PS-DESTM)-PhBCl2 was used, 4-O-benzyl ethers with 6-hydroxy unsubstituted were obtained in quantitative yield with excellent selectivity. (C) 2000 Elsevier Science Ltd. All rights reserved.