Concise Synthesis ofC2-Symmetrical 2,6-Disubstituted Morpholines byN → OBoc Migration under SL-PTC Conditions

A novel, straightforward synthesis of enantiomerically pure 2,6-disubstituted morpholines has been developed. The ring-opening of epoxides with TsNHBoc under solid−liquid phase transfer catalysis conditions occurred with N → O migration of the Boc group, affording an intermediate carbonate that has been easily transformed to morpholines.