The iodosulfonylation of (2E)-pentadienamides 1 affords stereoselectively (2E,4E)-5-tosylpentenamides2. 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).
(2 E)-
戊二烯酰胺1的
碘磺酰化可立体选择性地提供(2 E,4 E)-5-
甲苯磺酰基
戊烯酰胺2。这些二烯砜遭受
硫醇
钠和格利雅试剂的
甲苯磺酰基的亲核
乙烯基取代,以产生区域和立体选择性(2 E,4 E)-二酰胺3。该方法已应用于合成sarmentine(3bg)和Achillea amide(3cg)。