New and mildconditions 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
Various thiolesters are prepared in good yields by the reaction of thiols with acyloxypyridinium salts formed in situ from free carboxylic acids and 2-fluoro-1-methylpyridinium p-toluenesulfonate.