A compound having the formula (4): wherein
X is oxygen or sulfur, R9 and R10 are each a hydrogen or a protecting group, and R11 is an aliphatic hydrocarbon, a —COR12 group where R12 is alkyl, aryl or alkoxy, or a group of formula
wherein R5 and R6 are each hydrogen or hydroxyl, m is 1 to 4, and n is 0-2.
化合物的
化学式为(4):其中X为氧或
硫,R9和R10分别为氢或保护基,R11为脂肪烃、-COR12基团,其中R12为烷基、芳基或烷氧基,或者为式中的基团,其中R5和R6分别为氢或羟基,m为1至4,n为0-2。