(2E,4E)-5-Tosyl-2,4-pentadienamides: New dienic sulfones for the stereoselective synthesis of (2E,4E)-dienamides

Article abstract of DOI:10.1016/0040-4039(95)00594-3

The iodosulfonylation of (2E)-pentadienamides 1 affords stereoselectively (2E,4E)-5-tosylpentenamides 2. These dienic sulfones suffer nucleophilic vinylic substitution of the tosyl group by sodium thiolates and Grignard reagents to give regio- and stereo-selectively (2E,4E)-dienamides 3. This methodology has been applied to the synthesis of sarmentine (3bg) and an Achillea amide (3cg).