Question

How many $-OH$ group present in the final product.

Answer 1

The reaction of methylenecyclohexane osmium tetroxide followed by the action of sodium hydrogen sulphite forms 1-(hydroxymethyl)cyclohexanol. This is syn-hydroxylation reaction in which two -OH groups are added to the same side of carbon-carbon double bond.

Thus, the compound contains two $-OH$ group in the final product.