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

Participants

Reaction Steps

To a stirred suspension of (2S,5S)-tert-butyl 2-((tert-butyldimethylsilyloxy)methyl)-5-hydroxy-3-methyl-5,6-dihydropyridine-1(2H)-carboxylate (Intermediate 79, 5.48 g, 15.33 mmol), N-(allyloxy)-2-nitrobenzenesulfonamide (7.92 g, 30.65 mmol) and triphenylphosphine (12.06 g, 45.98 mmol) in toluene (20 mL) was cooled in an ice-bath and added dropwise (E)-diisopropyl diazene-1,2-dicarboxylate (8.91 ml, 45.98 mmol). Reaction was let warm up to rt and continued to stir at rt for 2 h. The reaction mixture was evaporated and the crude product was loaded onto silica gel, purified via flash chromatography (750 g, 0-50%) to obtain the desired product (7.05 g, 77%) as a yellow oil.

Provenance & Evidence