A general approach to medium-sized ring ethers via hydrolytic and oxidative kinetic resolutions: stereoselective syntheses of (−)-cis-lauthisan and (+)-isolaurepan

A short and enantioselective approach to medium ring ethers and its application to the syntheses of (−)-cis-lauthisan and (+)-isolaurepan are described. The synthetic strategy features Jacobson's Hydrolytic Kinetic Resolution (HKR), oxidative resolution of secondary alcohol, and highly diastereoselective Et₃SiH/TMSOTf-promoted reductive cyclization of a hydroxy ketone to give exclusively the different medium-sized cis-disubstituted cyclic ethers.