Meyers' bicyclic lactam formation under mild and highly stereoselective conditions

New and mild conditions to prepare chiral bicyclic lactams in high yields and high diastereoselectivities are reported herein. This approach based on the activation of the carboxylic acid by means of Mukaiyama's reagent is an excellent alternative to Meyers' dehydrating conditions and provide the main advantage to work at lower temperature (40 °C). Higher diastereoselectivity was obtained with 5,7-bicyclic lactams (de = 82% instead of 44% under standard dehydrating conditions).