A facile Synthesis of Polycyclic Spiranes via Pt-Catalyzed cyclization

Abstract

Spirane compound has a unique structure and is an important material in pharmaceutical and fine chemistry. We have developed an efficient and novel synthesis of a variety of polycyclic spiranes. The derivatives of 2-(oct-7-en-1-ynyl)benzaldehyde (1) were cycloisomerized into the corresponding cyclopropanes 2 which were isomerized into the corresponding spiranes 3 upon exposure to slight acidic medium such as p-toluenesulfonic acid or heat.