*4.2. One-Pot Two-Step Synthesis of Threo-9,10-Didhydroxystearic Acid* (**10**)

A suspension of Novozyme 435 (240 mg) in acetonitrile (48 mL), containing oleic acid (2.2 g, 91% purity, 7.1 mmol) and 35% H2O2 w/w (1.1 mL, 12.8 mmol) was shaken in an orbital shaker (160 rpm, 50 ◦C) for 5 h. The enzyme was removed by filtration, washed with acetonitrile, and stored at 4 ◦C to be re-used. A saturated solution of NaHSO3 (2 mL) was added to the filtrate, followed by the addition of 2 M H2SO4 (963 μL). After 15 h at room temperature, diol **10** was recovered by filtration (1.62 g, 72%, sum of two crystallization crops). 1H NMR (CD3OD, 400 MHz) [42]: δ = 3.45–3.35 (2H, m, 2CHOH), 2.29 (2H, t with *J* = 7.4 Hz, CH2COOH), 1.70–1.15 (26H, m, 13 CH2), 0.97–0.82 (3H, m, CH3). 13C NMR (CD3OD, 100.6 MHz) [42]: δ = 177.6, 75.29, 75.26, 35.0, 34.0, 33.9, 33.0, 30.8, 30.7, 30.6, 30.42, 30.37, 30.2, 27.04, 26.96, 26.1, 23.7, 14.4. GC/MS (EI) as a methyl ester, obtained by treatment with MeOH and

trimethylsilyldiazomethane 10% in hexane, tr = 23.85 min: m/z (%) = 294 (M<sup>+</sup> – 36, 1), 187 (48), 155 (100), 138 (30).
