SYNTHESIS OF 2-METHYLENETETRAHYDROPYRAN-3-OL DERIVATIVE, A KEY SEGMENT FOR CONVERGENT SYNTHESIS OF POLYCYCLIC ETHERS BASED ON SUZUKI-MIYAURA COUPLING

2-Methylenetetrahydropyran-3-ol derivative, a key segment for convergent synthesis of polycyclic ethers based on Suzuki-Miyaura coupling, was efficiently synthesized by two methods; (1) via SmI 2 -induced reductive cyclization of β-alkoxy vinyl sulfone with aldehyde followed by elimination of the sulfonyl group, and (2) via SmI 2 -induced cyclization of β-alkoxyvinyl sulfoxide with aldehyde followed by dehydration of the 2-hydroxymethyl group.