To a solution of tert-butyl (2S,3S)-3-(tert-butyldimethylsilyloxy)-1-(3-fluorophenyl)-4-oxobutan-2-ylcarbamate (0.148 g, 0.360 mmol) and (S)-2,2-dimethyl-6-neopentyl-1,2,3,4-tetrahydroquinolin-4-amine (0.0886 g, 0.360 mmol) in DCM (7.19 ml, 0.360 mmol) was added trimethoxymethane (0.394 ml, 3.60 mmol). The resulting solution was stirred for 1 hour at which time, sodium triacetoxyborohydride (0.229 g, 1.08 mmol) was added. The solution was then stirred for 30 minutes, quenched with saturated Rochelle's salt and stirred for an additional 20 minutes. The mixture was transferred to a sep. funnel containing DCM and H2O. The aqueous layer was washed 4× with DCM. The organic layers were combined, washed 1× with brine, dried with MgSO4, filtered and concentrated to afford the title compound. MS m/z: 642 (M+1).
