Patent ID: 6063917
Filing Date: 2000-05-16
Classification: C07D,C07K,Y02P

Abstract:
A process for the production of a compound of formula ##STR35## wherein R.sup.a denotes hydrogen or silyl;R.sup.b denotes a group of formula --OR.sup.e, whereinR.sup.e denotes hydrogen or alkyl; andR.sup.c and R.sup.d together denote a bond;in free form or in salt form,which process comprises the step of splitting, in the presence of ozone, the double bond in position 3 of the ring structure of a component of formula III ##STR36## wherein R.sub.2 and R.sub.3 are the same or different and independently of each other denote the hydrogen or an organic group, and X.sup.- denotes the anion of an inorganic or organic acid and optionally silylating the amine group in position 7 of the ring system.