Synthesis of sultam scaffolds via intramolecular oxa-Michael and diastereoselective Baylis-Hillman reactions.

A divergent synthetic approach to new sultams utilizing intramolecular oxa-Michael and Baylis-Hillman reactions of readily prepared vinyl sulfonamides and suitably protected amino alcohols, is reported. A variety of seven- and eight-membered ring sultam scaffolds were synthesized using oxa-Michael pathways, whereas both five- and six-membered rings were synthesized using Baylis-Hillman methods. Baylis-Hillman reactions proceed with good to excellent levels of diastereoselectivity, and oxa-Michael reactions leading to eight-membered ring sultams provide empirical evidence validating 8- endo-trig cyclization pathways.