LAUSR

Abstract The discovery and development of the vinylogous aldol reaction of N-sulfinyl metallodienamines with aldehydes and ketones is described. The diastereoselectivity of the reaction, first reported in 2017 as a key step in the total asymmetric synthesis of (−)-albocycline, has been corrected by Mosher ester analysis. The reaction has been optimized and the scope investigated, with yields ranging from 68–89% and diastereomeric ratios as high as 5.9:1. Extensive investigation into the mechanisms affecting stereoselectivity revealed that two stereochemical erosion pathways are operative when using LiHMDS and SnCl4. A transition state supported by DFT calculations has been advanced to rationalize the stereochemical course of the reaction.