Regio- and stereoselective synthesis of (+)-6-ketoeuryfuran, (+)-6-ketowinterin, and (−)-7-ketoeuryfuran from accessible labdane diterpenoids (+)-larixol and (−)-sclareol

Starting from (+)-larixol and (−)-sclareol, new syntheses of (+)-6-ketoeuryfuran, (+)-6-ketowinterin, and (−)-7-ketoeuryfuran have been elaborated in high yields. (+)-6-Ketowinterin was synthesized for the first time. Both euryfurans are excellent starting materials for the synthesis of important polyfunctional biologically active drimanic compounds.