Divergent synthesis of L-685,458 and its analogues involving one-pot intramolecular tandem sequence reaction

The one-pot tandem process of (2R,4R,SRS)-15 with Grignard reagents for highly diastereoselective synthesis of functionalized 2-piperidinone 1 was developed. Furthermore, the divergent syntheses of L-685,458 3 and its six analogues 20a-f have been conveniently achieved using this effective protocol as the key step.