Rearrangement Reaction of 2-Methyltetrahydropyrans Having a C1’-Mesyloxy Group on the C2-Side Chain with Zinc Acetate: Ring Expansion and Ring Opening Reactions

Rearrangements of four possible stereoisomers of 6-tert-butyl-2-(1'mesyloxy)ethyl-2-methyltetrahydropyran with Zn(OAc) 2 in aq.AcOH were investigated.Rearrangement-ring expansion and/or rearrangement-ring opening reactions took place depending on the stereostructure of the substrates.The cyclic ether system is an important component among a large number of organic compounds.Particularly, marine polycyclic ethers represented by brevetoxins 1 have recently attracted the attention of synthetic organic chemists due to their unusual structural framework, novel functionalities, and potent biological activities.The most characteristic feature of this class of marine natural products involves trans-fused polycyclic ether ring systems.Thus, various methods for constructing these systems have