Preparation, Purification and Regioselective Functionalization of Protoescigenin—The Main Aglycone of Escin Complex

Abstract

A two-step chemical process for controlled degradation of escin, affording a mixture of olean-12-ene sapogenins, was elaborated and scaled up. The main component of the mixture—protoescigenin—was isolated and purified, in the form of its corresponding monohydrate, without resource to chromatographic methods. This material was further converted into the high purity 3,24;16,22-di-O,O-isopropylidene derivative in a validated large scale laboratory process.

Keywords

• escin
• protoescigenin hydrates
• protoescigenin diacetonide
• polymorphism
• X-ray crystallography