Abstract: A process for the preparation of a compound of formula (I): ##STR1## which process comprises the reduction of a compound of formula (II): ##STR2## by catalytic hydrogenation using palladium on charcoal as catalyst.

Abstract: A process for the preparation of a compound of formula (I) or a pharmaceutically acceptable salt thereof: ##STR1## which process comprises reacting a compound of formula (II): ##STR2## wherein the amino group is optionally protected, Y is iodo, optionally substituted benzylthio or (phenacylmethyl)thio, with a compound of formula (III): ##STR3## wherein Q is a leaving group, R.sub.x and R.sub.y are protected hydroxymethyl or acyloxymethyl, or group(s) convertible to hydroxymethyl or acyloxymethyl; and R.sub.z is hydrogen or a group convertible thereto; and thereafter converting Y to X is hydroxy by means of hydrolysis, or to X is hydrogen by means of reduction; converting R.sub.x and R.sub.y when other than hydroxymethyl or acyloxymethyl, to hydroxymethyl or acyloxymethyl, optionally converting R.sub.x /R.sub.y hydroxymethyl to acyloxymethyl or vice versa, deprotecting the 2-amino group where necessary and converting R.sub.