Abstract: The present invention relates to a method of producing vicinal diols from a compound, the method characterised by the step of reacting the compound with a moderately strong acid in the presence one or more reagents capable of supplying hydroxyl groups wherein the moderately strong acid is a strongly reducing agent, but has a conjugate base that is a weak nucleophile. In preferred embodiments the moderately strong acid is hypophosphorous acid and the reagent(s) capable of supplying hydroxyl groups is 2-propanol in water, where 2-propanol is water soluable and organic. This method is particularly applicable to the production of vicinal diols of steroids, including lanosterol. Once vicinal diols of lanosterol diols are formed they are then capable of being further reacted to produce high purity lanosterol.