tert-butyl ((2R)-1-((((9H-fluoren-9-yl)methoxy)carbonyl)(2-(((tert-butyldimethylsilyl)oxy)methyl)-1-cyanoallyl)amino)but-3-en-2-yl)(benzyloxy)carbamate → (5R)-(9H-fluoren-9-yl)methyl 5-((benzyloxy)(tert-butoxycarbonyl)amino)-3-(((tert-butyldimethylsilyl)oxy)methyl)-2-cyano-5,6-dihydropyridine-1(2H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of tert-butyl ((2R)-1-((((9H-fluoren-9-yl)methoxy)carbonyl)(2-(((tert-butyldimethylsilyl)oxy)methyl)-1-cyanoallyl)amino)but-3-en-2-yl)(benzyloxy)carbamate (Intermediate 159, 3.32 g, 4.59 mmol) in toluene (150 mL) was bubbled with nitrogen for 15 minutes. Hoveyda-Grubbs Catalyst 2nd Generation (0.288 g, 0.46 mmol) was added and the mixture was bubbled with nitrogen for an additional 15 minutes. The resulting solution was heated under nitrogen at 90° C. for 2 days. The reaction mixture was evaporated. The residue was purified on silica gel column (0-30% EtOAc/hexane) to afford the title compound (1.300 g, 40.7%) as a light brown film.

Provenance & Evidence