Reacción #56720

Ecuación de reacción

THF

ethyl cyanoacetate

1-methylcyclopropane-methanol

PCC

→

ester

Rendimiento 26.2%

2-Cyano-3-(1-methyl-cyclopropyl)-acrylic acid ethyl ester

Rendimiento 26.2%

Disolventes

CH2Cl2

Condiciones de reacción

Tratamiento posterior

1. 1
   FiltraciónThe mixture was filtered through a 1 cm plug of silica gel under vacuum
2. 2
   Lavadorinsed with Et2O
3. 3
   ConcentraciónThe filtrate was concentrated to ca. 5 mL total volume
4. 4
   Otropartitioned between Et2O and sat. aq. NaHCO3
5. 5
   OtroThe phases were separated
6. 6
   Lavadothe organic phase washed with brine
7. 7
   Secadodried (MgSO4)
8. 8
   Concentraciónconcentrated

Procedimiento

To 1-methylcyclopropane-methanol (Aldrich, 1.13 mL, 11.6 mmol) in 50 mL CH2Cl2 was added neutral alumina (2.5 g) and then PCC (2.5 g, 11.6 mmol), and the mixture stirred 3 h at ambient temperature. The mixture was filtered through a 1 cm plug of silica gel under vacuum, and rinsed with Et2O. The filtrate was concentrated to ca. 5 mL total volume. To the residue was added THF (10 mL), ethyl cyanoacetate (1.2 mL, 11.3 mmol), piperidine (5 drops), and finally acetic acid (5 drops). The whole was stirred at ambient temperature overnight, then partitioned between Et2O and sat. aq. NaHCO3. The phases were separated and the organic phase washed with brine, dried (MgSO4), and concentrated. Flash chromatography of the residue (10→15% EtOAc/hexanes) provided 0.53 g (25%) of the ester as a colorless oil that crystallized on standing. Anal. Calcd for C10H13NO2: C, 67.02; H, 7.31; N, 7.82. Found: C, 66.86; H, 7.47; N, 7.70.

Fuente