Diastereoselective Synthesis of Enantiopure Morpholines by Electrophilic Selenium-Induced 6-exo Cyclizations on Chiral 3-Allyl-2-hydroxymethylperhydro-1,3-benzoxazine Derivatives

Enantiopure morpholine derivatives have been prepared by selenocyclofunctionalization of chiral 3-allyl-2-hydroxymethyl-substituted perhydro-1,3-benzoxazine derivatives. The cyclization occurs in high yields and diastereoselection, although the temperature of the reaction and the structure of the substituent at C-2 and the substitution pattern of the double bond can modify the regio- and stereochemistry of the final products.