Diisopropylethylamine → (R)-tert-butyl 3-((1S,2S)-2-(3,5-difluorobenzyl)-3-((S)-4-benzyl-2-oxooxazolidin-3-yl)-1-hydroxy-3-oxopropyl)-3,4-dihydro-isoquinoline-2(1H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of (S)-4-benzyl-3-(3-(3,5-difluorophenyl)propanoyl)oxazolidin-2-one (preparation D, 1.3 g, 3.77 mmol) in CH2Cl2 (50 mL) at −78° C. was added Bu2BOTf (4.90 ml, 4.90 mmol, 1M in CH2Cl2) and Hunig's base (972 mg, 7.54 mmol). The resulting mixture was brought up to 0° C. and stirred for 20 min. The mixture was cooled back to −78° C. and a solution of (R)-tert-butyl 3-formyl-3,4-dihydroisoquinoline-2(1H)-carboxylate (Step A (3), 1.10 g, 4.20 mmol) in CH2Cl2 (50 mL) was added dropwise. When the addition was complete, the mixture was allowed to warm to rt. After stirring at rt for 1 h, MeOH was added and the mixture was concentrated in vacuo. The crude mixture was purified by silica gel Flash chromatography to give 1.78 g (78% yield) of the title compound. MS (ESI)(M+H)+ 607.20.

Provenance & Evidence