Base-Promoted Tandem Ring-Opening/Ring-Closing of N-Alkynyl-2-oxazolidinones Enables Facile Synthesis of 2-Oxazolines

A K 2 CO 3 -promoted tandem ring-opening and ring-closing of N -alkynyl-2-oxazolidinones at r.t. has been described, affording 2-oxazolines in 42–99% yields without column chromatography purification.