Diastereoselective synthesis of aryl and alkyl trans-glycidic amides from pseudoephedrine-derived sulfonium salt. Chemospecific exo-tet ring closure for morpholin-3-ones

摘要

A regiospecific and high diastereoselective synthesis of trans-glycidic amides coming from a common pseudoephedrine sulfonium salt 2 precursor is presented. This is the first example in where the diastereoselectivity is controlled by a chiral noncyclic amide fragment. The epoxidation reaction provides alkyl or aryl glycidic amides in good to excellent yields and exclusive trans selectivity. Finally, through of a chemospecific 6-exo-tet ring closure of trans-epoxyamides we access to morpholin-3-ones densely functionalized with excellent chemical and stereochemical yields.