methyl [(2,3-difluorobenzyl) 5-acetamido-9-(4-chlorobenzamido)-3,5,9-trideoxy-D-glycero-α-D-galacto-2-nonulopyranosid]onate 、
2,2-二甲氧基丙烷 在
4-甲基苯磺酸吡啶 作用下,
以
乙腈 为溶剂,
以60%的产率得到methyl [(2,3-difluorobenzyl) 5-acetamido-9-(4-chlorobenzamido)-3,5,9-trideoxy-7,8-O-isopropylidene-D-glycero-α-D-galacto-2-nonulopyranosid]onate