Asymmetric cyclization of meso-diepoxides using chiral (salen)Co(III)OAc catalyst forming optically active 1,4-anhydropentitols and 2,5-anhydrohexitols

Abstract The asymmetric hydrations of meso -diepoxides, 1,2:4,5-dianhydro-3- O -methylxylitol 2 , 1,2:5,6-dianhydro-3,4-di- O -methylallitol 3 and 1,2:5,6-dianhydro-3,4-di- O -methylgalactitol 4 , were carried out using ( R , R )- 1 and ( S , S )- 1 . An optically active five-membered cyclic compound was selectively produced in good yield from 2 , but a mixture of the five- and six-membered cyclic compounds was obtained in the cases of 3 and 4 . The ees of all cyclic products exceeded 90%.