The invention relates to an improved method of preparing buprenorphine, a salt thereof, analogues of buprenorphine and their salts. In particular, the invention relates to a method of preparing buprenorphine and related products and salts in economic and ecologic ways having increased yields.

The invention relates to an improved method of preparing buprenorphine, a salt thereof, analogues of buprenorphine and their salts. In particular, the invention relates to a method of preparing buprenorphine and related products and salts in economic and ecologic ways having increased yields.

Disclosed are methods for preparing buprenorphine from, for example, compounds such as nororipavine and northebaine.

Disclosed are methods for preparing buprenorphine from, for example, compounds such as nororipavine and northebaine.

The present invention relates to compounds and their uses, in particular, compounds in the form of prodrugs that pro mote transport of a pharmaceutical agent to the lymphatic system and subsequently enhance release of the parent drug.

The present invention relates to compounds and their uses, in particular, compounds in the form of prodrugs that pro mote transport of a pharmaceutical agent to the lymphatic system and subsequently enhance release of the parent drug.

Disclosed are methods for preparing buprenorphine from, for example, compounds such as nororipavine and northebaine.

Disclosed are methods for preparing buprenorphine from, for example, compounds such as nororipavine and northebaine.

There is provided a novel process for the preparation of a compound of formula I, ##STR00001##
wherein R.sup.1, R.sup.2, W, Z and are as described in the description, by demethylation of a corresponding O-methyl derivative with a borohydride-based reagent. This process may be used in the preparation of buprenorphine.

There is provided a novel process for the preparation of a compound of formula I, ##STR00001##
wherein R.sup.1, R.sup.2, W, Z and are as described in the description, by demethylation of a corresponding O-methyl derivative with a borohydride-based reagent. This process may be used in the preparation of buprenorphine.