D-Proline → dibenzyl 1-((2S)-1-hydroxy-3-(tetrahydro-2H-pyran-3-yl)propan-2-yl)hydrazine-1,2-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 3-(tetrahydro-2H-pyran-3-yl)propanal (8.25 g, 0.058 mol) and dibenzyl azodicarboxylate (94%, 12.3 g, 0.041 mol) in MeCN (250 mL) at 0° C. was added (R-proline) (0.47 g, 0.0041 mol). After stirring the mixture at 0° C. for 15 hr, ethanol (100 mL) and NaBH4 (1.56 g, 0.041 mol) was added, and the mixture was stirred at 0° C. for 40 min. The reaction was quenched by slow addition of 10% aqueous citric acid (15 ml), and the whole solution was concentrated in vacuo. This residue was diluted with EtOAc (200 ml), washed with saturated brine (1×50 mL), dried over Na2SO4, and concentrated in vacuo to give the crude product, which was purified through column chromatography to give dibenzyl 1-((2S)-1-hydroxy-3-(tetrahydro-2H-pyran-3-yl)propan-2-yl)hydrazine-1,2-dicarboxylate (14.68 g, 81%).

Provenance & Evidence