Stereoselective synthesis of decytospolide A and B and their C-3 epimers, which have a 2,6-cis-tetrahydropyran ring, has been achieved in high stereoselectivity and yield. The oxypalladation of single diastereomers of 6-(benzyloxy)-7-hydroxydodec-2-enyl 2-naphthoates was optimized to give products with a 2,6-cis-tetrahydropyran ring with high diastereoselectivity and yield.