A compound of formula (I)
wherein
X represents a H atom, or a CH
2
OH group,
Y represents a H atom, or a CH
2
OH group,
but X and Y are not both CH
2
OH groups
and Ar is selected from
or a pharmaceutically acceptable salt thereof.
化合物的
化学式为(I),其中X代表氢原子或CH2OH基团,Y代表氢原子或CH2OH基团,但X和Y不同时为CH2OH基团,Ar从下列中选择,或其药学上可接受的盐。