hydrogenation of D-glucose to D-sorbitol, an organic reaction with nickel as a catalyst under high temperature and high pressure.
Microbial oxidation or fermentation of sorbitol to L-sorbose with acetobacter[1] at pH 4-6 and 30 °C.
protection of the 4 hydroxyl groups in sorbose by formation of the acetal with acetone and an acid to Diacetone-L-sorbose (2,3:4,6−Diisopropyliden−α−L−sorbose)
Organic oxidation with potassium permanganate followed by heating with water gives the 2-Keto-L-gulonic acid