Benzaldehyde → HCID 13289176, compound

HRID 1983433Notes

Reaction equation

HRID 1983433 reaction equation
[CH:1](=[O:4])[CH2:2][CH3:3].[CH:5](=[O:12])[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1.N1CCC[C@H]1C(O)=O>CN(C)C=O.C(OCC)(=O)C>[OH:12][C@H:5]([C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)[C@H:2]([CH3:3])[CH:1]=[O:4]

Participants

6

Reactant 3

HCID 240BenzaldehydeHCID 527PropanalHCID 145742L-Proline

Product 1

HCID 13289176HCID 13289176, compoundYield 81%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolvent2×HCID 8857Ethyl AcetateSolvent

Procedure

A solution of freshly distilled propionaldehyde (72 μL, 1.0 mmol) in 500 μL dimethylformamide pre-cooled to 4° C. was added slowly over the course of 16 h to a stirring suspension of benzaldehyde (1.02 mL, 10 mmol), L-proline (11.5 mg, 0.10 mmol) and 4.5 mL dimethylformamide at 4° C. After 16 hours, the resulting solution was diluted with ethyl acetate and washed successively with water and brine. The combined aqueous layers were back-extracted with 3 portions of dichloromethane. The organic layers were combined, dried over anhydrous Na2SO4, and then concentrated. Flash chromatography (4:1 hexanes:ethyl acetate) afforded the title compound as a clear, colorless oil in 81% yield (132 mg, 0.81 mmol), 99% ee and 3:1 anti:syn. Analytical data for this compound are identical in every respect to that previously reported (Mahrwald, supra) with the exception of optical rotation which has not been reported. [α]D=+9.1 (c=1.0, CHCl3). The product ratios were determined by HPLC analysis of the corresponding alcohol (obtained by NaBH4 reduction) using a Chiracel AD and AD guard column (1.0% isopropanol/hexanes, 1 mL/min); (2S,3S) anti isomer tr=147.5 min, (2R,3R) anti isomer tr, =161.1 min, (2R,3S) and (2S,3R) syn isomers tr=173.0, 200.0 min.

Workup

  1. washwashed successively with water and brine
  2. extractionThe combined aqueous layers were back-extracted with 3 portions of dichloromethane
  3. dry with materialdried over anhydrous Na2SO4
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-df9b3cef3a6a4ec78e2edb84d3ada911
Source dataset
uspto-grants-2009_06
Patent number
US07541456B2

Reaction notes

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