5-(4-Chloro-phenyl)-N-((1R,2R)-2-hydroxy-cyclohexyl)-6-(5-hydroxy-pentyloxy)-nicotinamide (0.23 g, 0.5 mmol) was dissolved in dichloromethane (15 mL). To the solution was added 2,2,6,6-tetramethyl-1-piperidinyloxy (1 mg), tetrabutylammoniumchlorid (1.5 mg), 5 mL of an aqueous solution of sodium bicarbonate (0.5 M) and potassium carbonate (0.05 M) and N-chlorosuccinimid (0.146 g, 1.1 mmol). The mixture was stirred for 72 h at room temperature and afterwards poured into citric acid (10%, 20 mL) and extracted with dichloromethane. Organic phases were pooled, dried with Na2SO4 and the solvent was evaporated. The residue (aldehyde contaminated with some starting alcohol) was redissolved in tent-butanol (5 mL). To the solution was added 2-methyl-butene solution (2 M in THF, 5 mL), sodium chlorite (210 mg), and sodium dihydrogenphosphate (0.345 g). The mixture was stirred for 72 h at room temperature and afterwards poured into citric acid (10%, 50 mL) and extracted with ethyl acetate. Organic phases were pooled, dried with MgSO4 and the solvent was evaporated. The residue was purified by column chromatography on silica (dichloromethane/methanol gradient) to yield 0.062 g of the title compound as a white foam, MS (ISP) 445.2 (M−H)+.
