Methanesulfonic acid (4aR,6S,7R,8S,8aR)-8-(tert-butyl-diphenyl-silanyloxy)-6-methoxy-2-phenyl-hexahydro-pyrano[3,2-d][1,3]dioxin-7-yl ester 在
N-溴代丁二酰亚胺(NBS) 、
barium carbonate 作用下,
以
四氯化碳 为溶剂,
反应 0.5h,
以81%的产率得到Benzoic acid (2S,3R,4S,5R,6S)-2-bromomethyl-4-(tert-butyl-diphenyl-silanyloxy)-5-methanesulfonyloxy-6-methoxy-tetrahydro-pyran-3-yl ester