Diisobutylaluminum hydride → Boc-(S)-3-Amino-3-phenylpropanal

HRID 1864894Notes

Reaction equation

HRID 1864894 reaction equation
[C:1]([O:5][C:6]([NH:8][C@H:9]([C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)[CH2:10][C:11](OCC)=[O:12])=[O:7])([CH3:4])([CH3:3])[CH3:2].CC(C[AlH]CC(C)C)C>>[O:12]=[CH:11][CH2:10][C@H:9]([NH:8][C:6](=[O:7])[O:5][C:1]([CH3:3])([CH3:2])[CH3:4])[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1

Participants

3

Reactant 2

HCID 14487Diisobutylaluminum hydrideHCID 15471178Ethyl (3R)-3-[(tert-butoxycarbonyl)amino]-3-phenylpropanoate

Product 1

HCID 11817535Boc-(S)-3-Amino-3-phenylpropanal

Conditions

Temperature
-78 °C

Procedure

To a dry, cooled (−78° C.) solution of ethyl (3S)-3-[(tert-butoxycarbonyl)amino]-3-phenylpropanoate from Step A (1.00 g, 3.41 mmol) was added a solution of DiBAl-H (6.82 mL, 6.82 mmol, 1 M in CH2Cl2) slowly over 30 min. After an additional 30 min of stirring at −78° C., the reaction was quenched by the rapid addition of saturated aqueous Rochelle's salt (32 mL). The cooling bath was then removed and the reaction was allowed to rapidly stir until a noticeable decrease in the amount of emulsion was observed. The layers were separated and the aqueous layer was extracted with CH2Cl2 (2×30 mL). Combined organics were dried over sodium sulfate, filtered and concentrated in vacuo to give an oil. This oil was purified by silica gel chromatography, eluting with a gradient of EtOAc:hexanes 5:95 to 40:60, to give the title compound. MS: m/z=150 (M−CO2C4H7).

Workup

  1. customthe reaction was quenched by the rapid addition of saturated aqueous Rochelle's salt (32 mL)
  2. customThe cooling bath was then removed
  3. stirringto rapidly stir until a noticeable decrease in the amount of emulsion
  4. customThe layers were separated
  5. extractionthe aqueous layer was extracted with CH2Cl2 (2×30 mL)
  6. dry with materialCombined organics were dried over sodium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo
  9. customto give an oil
  10. customThis oil was purified by silica gel chromatography
  11. washeluting with a gradient of EtOAc:hexanes 5:95 to 40:60

Sources & evidence

ORD record
ord-59b863f534594f7284d87a7832468f08
Source dataset
uspto-grants-2009_12
Patent number
US07625901B2

Reaction notes

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