(1S,4aS,8S,8aS)-8-Bromomethyl-6-oxo-1-((2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-hydroxymethyl-tetrahydro-pyran-2-yloxy)-5,6,8,8a-tetrahydro-1H,4aH-pyrano[3,4-c]pyran-4-carboxylic acid methyl ester 在
溴 、
potassium carbonate 作用下,
以
水 为溶剂,
以100%的产率得到(1S,3R,4R,5S,9R)-9-Bromo-7-oxo-3-((2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-hydroxymethyl-tetrahydro-pyran-2-yloxy)-4-vinyl-2,8-dioxa-bicyclo[3.3.1]nonane-9-carboxylic acid methyl ester