反应详情

A ˜1:1 mixture of (E) and (Z)-2-[[(phenylmethoxy)amino]methyl]-2-hexenoic acid methyl ester (3.95 g, 15 mmol), bis(norbornadiene)rhodium(I)tetrafluoroborate (56.1 mg, 0.15 mmol) and (1S,1′S,2R,2′R)-TangPhos (47.3 mg, 0.165 mmol) in de-oxygenated methanol (90 mL) in a Parr bottle is hydrogenated under H2 (45-55 psi) at RT for 24 hours. The reaction mixture is concentrated on Rotavap under reduced pressure (20 mbar) until no further solvent distills. The residue liquid is dissolved in a mixture of ethyl acetate/heptane (50/50, 10 mL) and filtered through a silica gel pad (˜12 g). The silica gel pad is rinsed with a mixture of ethyl acetate/heptane (50/50, 200 mL). The filtrates are combined and concentrated on Rotavap under reduced pressure (20 mbar) until no further solvent distills to afford 2-[[(phenylmethoxy)amino]methyl]-(2S)-hexanoic acid methyl ester (3.76 g, yield: 94%, S:R=98.0:2.0) as a liquid.

1. concentrationThe reaction mixture is concentrated on Rotavap under reduced pressure (20 mbar) until no further solvent
2. distillationdistills
3. dissolutionThe residue liquid is dissolved in a mixture of ethyl acetate/heptane (50/50, 10 mL)
4. filtrationfiltered through a silica gel pad (˜12 g)
5. washThe silica gel pad is rinsed with a mixture of ethyl acetate/heptane (50/50, 200 mL)
6. concentrationconcentrated on Rotavap under reduced pressure (20 mbar) until no further solvent
7. distillationdistills