methyl (2R)-2-[(2-methylpropan-2-yl)oxycarbonylamino]propanoate

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a cooled solution of (R)-methyl 2-(tert-butoxycarbonylamino)propanoate (40.0 g, 98.0 mmol) in DCM (200 mL) at −78° C. was added diisobutylaluminum hydride (208 mL, 1.0 M in THF) dropwise over 30 min. The reaction mixture was stirred at −78° C. for 1.5 h then quenched with water (50 mL). After warmed to rt, the white precipitate was removed by filtration over Celite. The organic layer was then washed with brine, dried (Na2SO4), and concentrated. The crude residue was purified by flash chromatography (petroleum ether:EtOAc, 10:1) to give (R)-tert-butyl 1-oxopropan-2-ylcarbamate (28.0 g, 82%). 1H NMR (DMSO-d6, 400 MHz) δ 9.43 (s, 1H), 7.33 (d, J=6.0 Hz, 1H), 3.85 (m, 1H), 1.39 (s, 9H), 1.12 (d, J=7.2 Hz, 3H). then quenched with water (50 mL) After warmed to rt the white precipitate was removed by filtration over Celite The organic layer was then washed with brine dried (Na2SO4) concentrated The crude residue was purified by flash chromatography (petroleum ether:EtOAc, 10:1)

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a cooled solution of (R)-methyl 2-(tert-butoxycarbonylamino)propanoate (40.0 g, 98.0 mmol) in DCM (200 mL) at −78° C. was added diisobutylaluminum hydride (208 mL, 1.0 M in THF) dropwise over 30 min. The reaction mixture was stirred at −78° C. for 1.5 h then quenched with water (50 mL). After warmed to rt, the white precipitate was removed by filtration over Celite. The organic layer was then washed with brine, dried (Na2SO4), and concentrated. The crude residue was purified by flash chromatography (petroleum ether:EtOAc, 10:1) to give (R)-tert-butyl 1-oxopropan-2-ylcarbamate (28.0 g, 82%). 1H NMR (DMSO-d6, 400 MHz) δ 9.43 (s, 1H), 7.33 (d, J=6.0 Hz, 1H), 3.85 (m, 1H), 1.39 (s, 9H), 1.12 (d, J=7.2 Hz, 3H). then quenched with water (50 mL) After warmed to rt the white precipitate was removed by filtration over Celite The organic layer was then washed with brine dried (Na2SO4) concentrated The crude residue was purified by flash chromatography (petroleum ether:EtOAc, 10:1)

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a cooled solution of (R)-methyl 2-(tert-butoxycarbonylamino)propanoate (40.0 g, 98.0 mmol) in DCM (200 mL) at −78° C. was added diisobutylaluminium hydride (208 mL, 1.0 M in THF) dropwise over 30 min. The reaction mixture was stirred at −78° C. for 1.5 h then quenched with water (50 mL). After warmed to rt, the white precipitate was removed by filtration over Celite. The organic layer was then washed with brine, dried (Na2SO4), and concentrated. The crude residue was purified by flash chromatography (petroleum ether: EtOAc, 10:1) to give (R)-tert-butyl 1-oxopropan-2-ylcarbamate (28.0 g, 82%). 1H NMR (DMSO-d6, 400 MHz) δ 9.43 (s, 1H), 7.33 (d, J=6.0 Hz, 1H), 3.85 (m, 1H), 1.39 (s, 9H), 1.12 (d, J=7.2 Hz, 3H). then quenched with water (50 mL) After warmed to rt the white precipitate was removed by filtration over Celite The organic layer was then washed with brine dried (Na2SO4) concentrated The crude residue was purified by flash chromatography (petroleum ether: EtOAc, 10:1)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (R)-1-Methyl-3-phenylpropanamine hydrochloride was prepared by first esterifying N-(tert-butyloxycarbonyl)-D-alanine with diazomethane, then reducing the resulting N-(tert-butyloxycarbonyl)-D-alanine methyl ester with diisobutylaluminum hydride, then condensing the resulting N-(tert-butyloxycarbonyl)-D-alaninal with benzylidenetriphenylphosphonium ylide, then hydrogenating over palladium catalyst the resulting [R-(E)]-N-(tert-butyloxycarbonyl)-1-methyl-3-phenyl-2-propenamine having m.r. 86°-88° C. and [α]D25 +54.0° (c=1, methanol), and finally deprotecting with hydrogen chloride in dioxane the resulting (R)-N-(tert-butyloxycarbonyl)-1-methyl-3-phenylpropanamine having m.r. 74°-76° C. and [α]D25 +7.2° (c=1, methanol). ##STR16##

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a cooled solution of (R)-methyl 2-(tert-butoxycarbonylamino)propanoate (40.0 g, 98.0 mmol) in DCM (200 mL) at −78° C. was added diisobutylaluminum hydride (208 mL, 1.0 M in THF) dropwise over 30 min. The reaction mixture was stirred at −78° C. for 1.5 h then quenched with water (50 mL). After warmed to rt, the white precipitate was removed by filtration over Celite. The organic layer was then washed with brine, dried (Na2SO4), and concentrated. The crude residue was purified by flash chromatography (petroleum ether:EtOAc, 10:1) to give (R)-tert-butyl 1-oxopropan-2-ylcarbamate (28.0 g, 82%). 1H NMR (DMSO-d6, 400 MHz) δ 9.43 (s, 1H), 7.33 (d, J=6.0 Hz, 1H), 3.85 (m, 1H), 1.39 (s, 9H), 1.12 (d, J=7.2 Hz, 3H). then quenched with water (50 mL) After warmed to rt the white precipitate was removed by filtration over Celite The organic layer was then washed with brine dried (Na2SO4) concentrated The crude residue was purified by flash chromatography (petroleum ether:EtOAc, 10:1)

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a cooled solution of (R)-methyl 2-(tert-butoxycarbonylamino)propanoate (40.0 g, 98.0 mmol) in DCM (200 mL) at −78° C. was added diisobutylaluminium hydride (208 mL, 1.0 M in THF) dropwise over 30 min. The reaction mixture was stirred at −78° C. for 1.5 h then quenched with water (50 mL). After warmed to rt, the white precipitate was removed by filtration over Celite. The organic layer was then washed with brine, dried (Na2SO4), and concentrated. The crude residue was purified by flash chromatography (petroleum ether: EtOAc, 10:1) to give (R)-tert-butyl 1-oxopropan-2-ylcarbamate (28.0 g, 82%). 1H NMR (DMSO-d6, 400 MHz) δ 9.43 (s, 1H), 7.33 (d, J=6.0 Hz, 1H), 3.85 (m, 1H), 1.39 (s, 9H), 1.12 (d, J=7.2 Hz, 3H). then quenched with water (50 mL) After warmed to rt the white precipitate was removed by filtration over Celite The organic layer was then washed with brine dried (Na2SO4) concentrated The crude residue was purified by flash chromatography (petroleum ether: EtOAc, 10:1)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (R)-1-Methyl-3-phenylpropanamine hydrochloride was prepared by first esterifying N-(tert-butyloxycarbonyl)-D-alanine with diazomethane, then reducing the resulting N-(tert-butyloxycarbonyl)-D-alanine methyl ester with diisobutylaluminum hydride, then condensing the resulting N-(tert-butyloxycarbonyl)-D-alaninal with benzylidenetriphenylphosphonium ylide, then hydrogenating over palladium catalyst the resulting [R-(E)]-N-(tert-butyloxycarbonyl)-1-methyl-3-phenyl-2-propenamine having m.r. 86°-88° C. and [α]D25 +54.0° (c=1, methanol), and finally deprotecting with hydrogen chloride in dioxane the resulting (R)-N-(tert-butyloxycarbonyl)-1-methyl-3-phenylpropanamine having m.r. 74°-76° C. and [α]D25 +7.2° (c=1, methanol). ##STR16##