In method A,2,3-O-isopropylidene-5-O-pivaloyl-D-ribofuranose reacted with tetraethyl methylenediphosphonate(TEMDP) to give 1-(diethyl)-2,3-O-isopropylidene-5-O-pivaloyl-D-ribofuranosyl phosphonate.

• 方法A用2,3-O-异丙叉基-5-O-三甲基乙酰基-D-呋喃核糖与四乙基亚甲基二膦酸酯(TEMDP)反应,得到2,3-O-异丙叉基-5-O-三甲基乙酰基-1-亚甲基膦酸二乙酯-D-呋喃核糖,然后用乙醇钠脱去酰基保护基。