Dimethyl malonate → Dimethyl 2-(3-oxocyclopentyl)malonate

HRID 1093092Notes

Reaction equation

HRID 1093092 reaction equation
[C:1]1(=[O:6])[CH2:5][CH2:4][CH:3]=[CH:2]1.[C:7]([O:14][CH3:15])(=[O:13])[CH2:8][C:9]([O:11][CH3:12])=[O:10]>C1(C)C=CC=CC=1.N1CCCN2CCCN=C12>[O:6]=[C:1]1[CH2:5][CH2:4][CH:3]([CH:8]([C:7]([O:14][CH3:15])=[O:13])[C:9]([O:11][CH3:12])=[O:10])[CH2:2]1

Participants

5

Reactant 2

HCID 7943Dimethyl malonateHCID 135882-Cyclopenten-1-one

Product 1

HCID 11608197Dimethyl 2-(3-oxocyclopentyl)malonateYield 90.3%

Reagents, catalysts & solvents 2

HCID 79873TriazabicyclodeceneCatalystHCID 1140TolueneSolvent

Procedure

Tetrahedron Letters 2005, 46, 6875-6878. To a solution of cyclopent-2-enone (99.82 g, 1216 mmol) and dimethyl malonate (560 mL, 4887 mmol) in dry toluene (1000 mL) was added 2,3,4,6,7,8-hexahydro-1H-pyrimido[1,2-a]pyrimidine (5.10 g, 36.6 mmol). The reaction was stirred at room temperature under nitrogen for 16 hrs, then concentrated under reduced pressure to ˜½ volume. The crude product was filtered through a short path of silica gel (3.5×4 cm), eluting with ethyl acetate. The filtrate was concentrated under vacuum pump rotary evaporation (70-75° C. water bath) for 2 hrs, affording the target compound (247.7 g, 1098 mmol, 90% yield). 1H NMR (500 MHz, CDCl3) δ ppm 3.76 (3 H, s), 3.74 (3 H, s), 3.37 (1 H, d, J=9.46 Hz), 2.80-2.91 (1 H, m), 2.49 (1 H, dd, J=18.31, 7.63 Hz), 2.29-2.37 (1 H, m), 2.15-2.28 (2 H, m), 2.00 (1 H, ddd, J=18.46, 10.99, 1.37 Hz), 1.58-1.71 (1 H, m).

Workup

  1. concentrationconcentrated under reduced pressure
  2. filtrationThe crude product was filtered through a short path of silica gel (3.5×4 cm)
  3. washeluting with ethyl acetate
  4. concentrationThe filtrate was concentrated under vacuum pump rotary evaporation (70-75° C. water bath) for 2 hrs

Sources & evidence

ORD record
ord-f3265878156642979398bb29de0813bc
Source dataset
uspto-grants-2012_03
Patent number
US08129398B2

Reaction notes

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