Concise Stereoselective Total Synthesis of (-)-Hedycoropyran A.

A concise and stereoselective total synthesis of (-)-hedycoropyran A was accomplished in a substrate-controlled manner from a readily available alkene. Highlights of the synthesis include a highly diastereoselective dehydrogenative cycloetherification to construct the trans -2-aryl-6-alkyl-3,6-dihydro-2 H -pyran framework and late-stage substrate-controlled trans -dihydroxylation at C(3,4).