Stereoselective Total Synthesis of Decytospolides A and B Starting from D-Mannitol

The stereoselective total synthesis of decytospolides A and B, two naturally occurring pyran derivatives, has been achieved using D‐mannitol as the starting material. The intramolecular oxa‐Michael reaction has been employed to construct the tetrahydropyran ring of the molecules and Weinreb amide formation to generate their side chain with a keto function.