Catalytic One-Pot Osmylation of Cyclohexadienes: Stereochemical and conformational studies of the resulting polyols

Catalytic double osmylation is described for a series of cyclohexadienes in acetone/H2O in the presence of the co-oxidant N-methylmorpholine N-oxide (NMO). The formation of polyols occurred stereospecifically with cyclohexadienes 3, 7, and 11 a, leading thereby to tetrols 5a, and 9a and to allo-inositol (14a), respectively. To the contrary, trans-cyclohexadiene-diol 15a gave a mixture of the stereoisomeric inositols 18a (epi), 19a (neo), and 20a (chiro). High-field NMR let to clearcut conformational analyses of the polyhydroxylated derivatives.