Bis(2-pyridyl) ketone → (Z)-Hex-2-enoic acid

HRID 1458434Notes

Reaction equation

HRID 1458434 reaction equation
N1C=CC=C[C:2]=1[C:7]([C:9]1[CH:14]=[CH:13][CH:12]=[CH:11]N=1)=[O:8].[Br-].[C:16]([CH2:19][CH2:20][CH2:21][CH2:22][P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)([OH:18])=[O:17].CC([O-])(C)C.[K+]>C1COCC1>[C:7]([OH:17])(=[O:8])/[CH:9]=[CH:14]/[CH2:13][CH2:12][CH3:11].[C:16]([OH:18])(=[O:17])/[CH:19]=[CH:20]\[CH2:21][CH2:22][CH3:2]

Participants

6

Reactant 3

HCID 88065Bis(2-pyridyl) ketoneHCID 161236(4-Carboxybutyl)triphenylphosphonium bromideHCID 23665647Potassium tert-butoxide

Product 2

HCID 52827072-Hexenoic acid, (2E)-HCID 12467038(Z)-Hex-2-enoic acidYield 88.6%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Prepared as above from 150.0 mg (0.35 mmol) of the pyridyl ketone, 308.2 mg (0.70 mmol) of (4-carboxybutyl)triphenylphosphonium bromide, and 1.4 mL (1.4 mmol) of 1.0M t-BuOK in 1.5 mL of THF at 0° C. for 1.5 hr. Flash chromatography followed by preparative HPLC with MeOH-AcOH-CH2 Cl2 (3.5:1.5:95) furnished 107.9 mg 60.2%) of (E)-hexenoic acid and 35.4 mg (19.8%) of (Z)-hexenoic acid (E/Z=3:1). The title (E)-isomer was characterized as follows: mp 86°-90° C.; 1H NMR (CDCl3) δ8.55 (br s, 1H), 8.45 (d, J=4.7 Hz, 1H), 8.25 (s, 1H), 8.04 (d, J=8.1 Hz, 2H), 7.47 (d, J=8.0 Hz, 1H), 7.29 (d, J=8.2 Hz, 2H), 7.21 (m, 1H), 7.12 (distorted t, J=~5.1 Hz, 1H), 6.19 (t, J=7.5 Hz, 1H), 3.44 (dt, J=7.0, 6.7, Hz, 2H), 2.34 (t J=7.1 Hz, 2H), 2.25 (dt, J=7.4, 7.3 Hz, 2H), 1.68-0.82 (m, 19H); FDMS 516 (M+1). Anal. (C31 H37N3O4) C, H, N.

Sources & evidence

ORD record
ord-5743270f17a847629a741c51a8f70247
Source dataset
uspto-grants-1998_12
Patent number
US05849922

Reaction notes

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