First total synthesis of (+)-apotrisporin E and (+)-apotrientriols A–B: a cyclization approach to apocarotenoids

Abstract

The first total synthesis of the natural apocarotenoids (+)-apotrisporin E (1) and (+)-apotrientriols A and B (2–3) has been accomplished. The structure, relative stereochemistry and the assignation of the absolute configuration have been confirmed. This is a fast and easy access to this family of natural products whose key steps are a diastereoselective cyclization and a HWE olefination to attach the dienic side chain. This work also opens the door to the synthesis of other apocarotenoids such as trisporols and trisporic acids.