I know that alkenes when treated with OsO4 in pyridine undergo syn 1,2-dihydroxylation. This forms an osmate ester which when treated with NaHSO3 in water gives a diol by syn addition.
However, in one of the problems, 1-methylcyclohexene treated with OsO4 and then H2O2 gave a diol by anti addition.
The attempt at a solution
I think that it won't add by anti fashion in the first place. Even if it is possible, would it be by some free radical mechanism?