Triphenylphosphine → (2S,5R)-tert-butyl 5-(N-(allyloxy)-2-nitrophenylsulfonamido)-2-((tert-butyldimethylsilyloxy)methyl)-3-ethyl-5,6-dihydropyridine-1(2H)-carboxylate

Participants

Reaction Steps

To a stirred suspension of (2S,5S)-tert-butyl 2-((tert-butyldimethylsilyloxy)methyl)-3-ethyl-5-hydroxy-5,6-dihydropyridine-1(2H)-carboxylate (Intermediate 208, 6.36 g, 17.12 mmol), N-(allyloxy)-2-nitrobenzenesulfonamide (Intermediate 9) (8.84 g, 34.23 mmol) and triphenylphosphine (13.47 g, 51.35 mmol) in toluene (25 mL) at 0° C. was added dropwise (E)-diisopropyl diazene-1,2-dicarboxylate (9.95 ml, 51.35 mmol). The reaction mixture was warmed to room temperature and stirred for 30 minutes. Silica gel chromatography (0-40% ethyl acetate/hexanes) afforded the title compound (7.00 g, 66.8%) as a yellow oil.

Provenance & Evidence