Maleic Anhydride → HCID 11427626, compound

HRID 968985Notes

Reaction equation

HRID 968985 reaction equation
[CH3:1][O:2][C:3](=[O:29])[CH2:4][CH2:5][CH2:6][CH2:7][CH2:8]/[CH:9]=[C:10]1\[CH:11]([CH2:21][CH2:22][CH2:23][CH2:24][CH2:25][CH2:26][CH2:27][CH3:28])[CH:12]2[CH:17]([C:18]\1=[O:19])C1CC2C=C1.C1(=O)OC(=O)C=C1.C[Al](Cl)Cl>ClCCl>[CH3:1][O:2][C:3](=[O:29])[CH2:4][CH2:5][CH2:6][CH2:7][CH2:8]/[CH:9]=[C:10]1\[CH:11]([CH2:21][CH2:22][CH2:23][CH2:24][CH2:25][CH2:26][CH2:27][CH3:28])[CH:12]=[CH:17][C:18]\1=[O:19].[CH3:1][O:2][C:3](=[O:29])[CH2:4][CH2:5][CH2:6][CH2:7][CH2:8]/[CH:9]=[C:10]1/[CH:11]([CH2:21][CH2:22][CH2:23][CH2:24][CH2:25][CH2:26][CH2:27][CH3:28])[CH:12]=[CH:17][C:18]/1=[O:19]

Participants

6

Reactant 3

HCID 7923Maleic AnhydrideHCID 101908Methylaluminum dichlorideHCID 69484754HCID 69484754, compound

Product 2

HCID 11427626HCID 11427626, compoundYield 69%HCID 69484757HCID 69484757, compoundYield 17%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
50 °C

Procedure

Under nitrogen in oven dried glassware, a mixture of 7 (200 mg, 0.50 mmol, 1 eq.) and maleic anhydride (245 mg, 2.50 mmol, 5 eq.) in dichloromethane (20 cm3) was treated with a 1 M solution of MeAlCl2 in hexanes (0.5 cm3, 0.50 mmol, 1 eq.) and heated to 50° C. (oil bath temperature) for 6 hours. The reaction mixture was cooled to room temperature and silica (ca. 2 g) was added. The solvent was removed under reduced pressure and the residue was purified by flash column chromatography (Hex-EtOAc; 4:1) affording the title compound (8) (115 mg, 69%) and its cis-isomer (9) (28 mg, 17%) both as clear liquids. 7-[2-Octyl-5-oxocyclopent-3-en-(E)-ylidene]heptanoic acid methyl ester (8): Rf=0.2 (Hex-EtOAc; 3:1); δH (400 MHz, CDCl3) 0.88 (3H, t, J 6.5 Hz, CH3), 1.21-1.34 (12H, m, CH2), 1.34-1.42 (2H, m, CH2), 1.46-1.54 (1H, m, CHAHB), 1.52 (2H, pent, J 7.5 Hz, CH2), 1.65 (2H, pent, J 7.5 Hz, CH2), 1.76-1.86 (1H, m, CHAHB), 2.18-2.32 (2H, m, 6-CH2), 2.31 (2H, t, J 7.5 Hz, 2-CH2), 3.44-3.49 (1H, m, 2-CH), 3.66 (3H, s, CH3), 6.32 (1H, dd, J 2.0, 6.0 Hz, 4-CH), 6.53 (1H, t, J 7.5 Hz, 7-CH), 7.50-7.57 (1H, m, 3-CH); δC (100 MHz, CDCl3) 14.0, 22.6, 24.7, 25.9, 28.3, 28.85, 28.9, 29.2, 29.4, 29.7, 31.8, 32.5, 33.9, 43.3, 51.4, 134.8, 135.1, 138.1, 164.9, 174.0, 196.9; m/z (CI) 352 (MNH4+, 5%), 335 (MH+, 100%); Found C, 75.33; H, 10.35%, C21H34O3 requires C, 75.40; H, 10.26%. 7-[2-Octyl-5-oxocyclopent-3-en-(Z)-ylidene]heptanoic acid methyl ester (9): Rf=0.25 (Hex-EtOAc; 3:1); δH (400 MHz, CDCl3) 0.88 (3H, t, J 6.5 Hz, CH3), 1.19-1.32 (20H, m, CH2), 2.29 (2H, t, J 7.5 Hz, 2-CH2), 2.80 (2H, q, J 7.5 Hz, 6-CH2), 3.23-3.28 (1H, m, 2-CH), 3.67 (3H, s, CH3), 5.99 (1H, t, J 7.5 Hz, 7-CH), 6.26 (1H, dd, J 2.0, 6.0 Hz, 4-CH), 7.42 (1H, dd, J 2.5, 6.0 Hz, 3-CH); δC (100 MHz, CDCl3) 14.1, 22.6, 24.8, 26.4, 27.0, 28.8, 29.0, 29.2, 29.4, 29.8, 31.8, 33.6, 34.0, 45.5, 51.4, 136.3, 137.1, 139.8, 160.3, 174.1, 198.2; m/z (CI) 352 (MNH4+, 10%), 335 (MH+, 100%).

Workup

  1. customUnder nitrogen in oven dried glassware
  2. temperatureThe reaction mixture was cooled to room temperature
  3. additionsilica (ca. 2 g) was added
  4. customThe solvent was removed under reduced pressure
  5. customthe residue was purified by flash column chromatography (Hex-EtOAc; 4:1)

Sources & evidence

ORD record
ord-b5261b8ab26d43518a68e0f8549f208a
Source dataset
uspto-grants-2007_12
Patent number
US07304186B2

Reaction notes

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