Molecule 21 (36 mg, 0.09mmol) was dissolved in MeOH (1.5 mL). The mixture was cooled to –78 °C. Sodium borohydride (10.5 mg, 0.28 mmol) was then added to the mixture. The mixture was then stirred for 10 min at –78 °C and then for 20 min at 0 °C. After mixing, a TLC was taken and indicated that the starting material was completely consumed. Raney-Ni (850 mg, washed 4 times with MeOH) was then added. The mixture was then heated under *reflux* for 20 min. After cooling, the mixture was filtered through *celite filtration* and the filtrate was concentrated under reduced pressure. The residue was purified with *column chromatography* with a 10:1 mixture of hexanes/ethyl acetate. The column resulted in molecule 20 as an oil (25 mg, 95% yield, >15:1 stereoselectivity as indicated by 1H NMR spectroscopy).

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