Total Synthesis of Terpioside B

The first total synthesis of terpioside B ( 1 ) has been accomplished. Key steps include the stereoselective installments of a set of challenging 1,2- cis -glycosidic linkages. Thus, α(1,4)-linked D-galactoside was effectively constructed from a 1,2-anhydrogalactose donor and an unprotected 1,6-anhydrogalactose acceptor by using a boron-mediated aglycon delivery (BMAD) method. In addition, α-L-fucofuranosides were stereoselectively and simultaneously constructed by remote group-assisted 1,2- cis -α-stereoselective glycosylations.