Synthesis of phenethyl 3-D-glycopyranoside

By following the reported procedure, coupling reaction of 70 and 2,3,4-tri-O-acetyl-a-L-arabinopyranosyl bromide in the presence of AgOTf and tetramethy-lurea (TMU) gave the coupled product (72) in 73% yield. Finally, treatment of 72 with K2CO3 in MeOH provided the synthetic phenethyl 6-O-a-L-arabinopyranosyl-p-D-glucopyranoside (66) in 86% yield. 

The tert-butyldimethylsilyl (TBDMS) protection of 50 gave a silyl ether 

The coupling reaction of 78 with 2 equivalents of the reported 2,3,4-tri-O-benzoyl-a-L-rhamnopyranosyl bromide in the presence of AgOTf and TMU in CH2CI2 gave the coupled product (81) in 56% yield. Finally, treatment of 81 with NaOMe in MeOH-THF provided the synthetic (3Z)-hexenyl 6-O-a-L-rhamnopyranosyl-p-D-gluco-pyranoside (76) in 96% yield. 

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