TOTAL SYNTHESIS OF (8'R)-COROSSOLINE AND (8'S)-COROSSOLINE

A convergent stereoselective total synthesis of (8'R)- and (8'S)-coros soline (1) has been performed via a multi-step process. Comparison of the mp, [alpha](D), ir and nmr data of both synthetic materials with t hose reported for natural corossoline did not allow for the strict det ermination of the configuration at the C-8' hydroxyl group of 1. Howev er, a slight chemical shift difference at the C-8' methine proton was observed in the H-1-nmr spectra of the corresponding tris-MTPA esters of synthetic (8'R)- and (8'S)-1, indicating that if the tris-MTPA este r of natural 1 is available, the stereochemistry at the C-8' hydroxyl group of corossoline will be established.