II [0204] wherein Z1 is a suitable leaving group, such as halogen or Y1SO2O???; [0205] (b) for compounds of formula I in which q is 0 and R6 and R7 both represent H, reduction of a compound of formula IV, [0206] using a suitable reducing agent; [0207] (c) for compounds of formula I in which q is 0 and R9 and R10 both represent H, reduction of a compound of formula V, [0208] using a suitable reduci