Among the different types of the olefin metathesis reactions that have been developed, ring-rearrangement metathesis (RRM) has been proven to be especially powerful. RRM has been applied in the synthesis of polycyclic ethers, N-heterocycles, fused carbocycles and various natural products. Based on the first example of diastereoselective ring-closing metathesis we were interested in extending this methodology to create also new stereocenters by RRM. In this lecture we report on ring-rearrangements of prochiral rings 1 or 3 with stereoinformation in the side chain leading to carbo- and heterocycles.

Scheme 1: Diastereoselective RRM.

The challenge for such a process is to shift the reaction to the desired product. Diastereoselectivities are catalyst depending. The concept has been applied to the synthesis of various alkaloids like (–)-centrolobine or (–)-porantheridine.