Oxalic Acid → Sinensal

HRID 1658432Notes

Reaction equation

HRID 1658432 reaction equation
C([Li])CCC.C(N[CH:10]([CH3:12])[CH3:11])(C)C.[CH3:13][C:14](=[CH:19][CH2:20][CH2:21][C:22]([CH:24]=[CH2:25])=[CH2:23])[CH2:15][CH2:16][CH:17]=O.C(O)(=O)C(O)=[O:28]>CCCCCC.O.CCOCC>[CH3:13]/[C:14](/[CH2:15][CH2:16]/[CH:17]=[C:10](/[CH:11]=[O:28])\[CH3:12])=[CH:19]\[CH2:20][CH2:21][C:22]([CH:24]=[CH2:25])=[CH2:23]

Participants

8

Reactant 4

HCID 971Oxalic AcidHCID 7912DiisopropylamineHCID 54018124HCID 54018124, compoundHCID 178418339Butyllithium

Product 1

HCID 5281535SinensalYield 70%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 3283Diethyl EtherSolvent4×HCID 8058HexaneSolvent

Procedure

A solution containing 600 ml. of absolute ether and 640 g. (1.5 moles) of butyl lithium in the form of a 15% solution in hexane was cooled to -10°. In the course of one hour, a solution of 128 g. of diisopropylamine (1.265 moles) in 600 ml. of absolute ether was added with stirring and under nitrogen, then the temperature was allowed to rise to 0°, and stirring was continued for an additional 1/2 hour. The solution was again cooled to -10° and a solution containing 208 g. of propylidene-cyclohexylimine (1.5 moles, b.p. 56°-58°/15 Torr) in 600 ml. of ether was added dropwise over a period of one hour. The mixture was stirred for one hour at 0°, then cooled to -65°, there was then added thereto, within a period of 1/2 hour, 225 g. of 4-methyl-8-vinyl-4,8-nonadienal (1.265 moles) dissolved in 600 ml. of ether, while maintaining the temperature between -66° and -62°. The temperature was allowed to come back to 25° in the course of one hour. The reaction mixture was then poured into 8.1 of water at 0° that contained 600 g. of oxalic acid, under stirring. The organic layer was separated and the aqueous phase extracted twice with ether ( 2 1.). The extracts were washed with aqueous 5% bicarbonate and with water. After drying and evaporation a yield of 70% of crude β-sinensal was obtained. B.p. 100°-111°/0.04 Torr. An analytical sample was prepared by chromatography on silica with a 3% solution of ethyl acetate in hexane (v/v) as the eluent; b.p. 88°-89°/0.02 Torr. Spectral measurements; IR (CHCl3): 3090, 2710, 1800, 1680, 1640, 1590, 995, 905 cm-1, UV (EtOH): 2260 A (ε= 34,000). NMR (CCl4): 9.33 ppm (1 H, s), 6.37 ppm (1 H, t, J = 6 cps), 6.30 ppm (1 H, d of d, J = 17 and 10 cps), 4.8 - 5.4 ppm (5 H, m), 1.9 - 2.6 ppm (8 H, m), 1.69 ppm (3 H, s broad), 1.61 ppm (3 H, s broad).

Workup

  1. additionA solution containing 600 ml
  2. customIn the course of one hour
  3. customto rise to 0°
  4. stirringstirring
  5. temperatureThe solution was again cooled to -10°
  6. additiona solution containing 208 g
  7. stirringThe mixture was stirred for one hour at 0°
  8. temperaturecooled to -65°
  9. additionthere was then added
  10. waitwithin a period of 1/2 hour
  11. customto come back to 25° in the course of one hour
  12. customThe organic layer was separated
  13. extractionthe aqueous phase extracted twice with ether ( 2 1.)
  14. washThe extracts were washed with aqueous 5% bicarbonate and with water
  15. customAfter drying

Sources & evidence

ORD record
ord-a11ffeb81db7404e917cbaabe415edf3
Source dataset
uspto-grants-1976_06
Patent number
US03963783

Reaction notes

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