Water → Methyl rac-4,4-ethylenedioxy-1,2,3,4-tetrahydro-2-hydroxy-5,8-dimethoxynaphthalene-2-carboxylate

HRID 463464Notes

Reaction equation

HRID 463464 reaction equation
C(NC(C)C)(C)C.C([Li])CCC.[CH2:13]1[CH2:34][O:33][C:15]2([C:24]3[C:19](=[C:20]([O:27][CH3:28])[CH:21]=[CH:22][C:23]=3[O:25][CH3:26])[CH2:18][CH:17]([C:29]([O:31][CH3:32])=[O:30])[CH2:16]2)[O:14]1.[OH2:35]>O1CCCC1.CCCCCC>[CH2:34]1[CH2:13][O:14][C:15]2([C:24]3[C:19](=[C:20]([O:27][CH3:28])[CH:21]=[CH:22][C:23]=3[O:25][CH3:26])[CH2:18][C:17]([OH:35])([C:29]([O:31][CH3:32])=[O:30])[CH2:16]2)[O:33]1

Participants

7

Reactant 4

HCID 962WaterHCID 7912DiisopropylamineHCID 13264135Methyl 4,4-ethylenedioxy-1,2,3,4-tetrahydro-5,8-dimethoxynaphthalene-2-carboxylateHCID 178418339Butyllithium

Product 1

HCID 13264136Methyl rac-4,4-ethylenedioxy-1,2,3,4-tetrahydro-2-hydroxy-5,8-dimethoxynaphthalene-2-carboxylateYield 58%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolvent

Conditions

Temperature
0 °C

Procedure

(a) To a solution of 84 ml of diisopropylamine in 250 ml of dry tetrahydrofuran at -78° C. under argon was added a solution of n-butyl lithium (39 ml, 1.6 mol) in hexane. The mixture was stirred for 10 minutes and then a solution of 12.32 g of methyl 4,4-ethylenedioxy-1,2,3,4-tetrahydro-5,8-dimethoxynaphthalene-2-carboxylate in 75 ml of dry tetrahydrofuran was added rapidly. The mixture was held at -78° C. while stirring for 50 minutes and then 27.8 g of finely ground diperoxo-oxohexamethylphosphoramidomolybdenum (VI) pyridine were added. After a further 80 minutes, the mixture was warmed to 0° C. and stirred for 20 minutes before the addition of 400 ml of water. After 10 minutes, most of the tetrahydrofuran was evaporated in vacuo and the aqueous residue was extracted with five 200 ml portions of ethyl acetate. The combined ethyl acetate extracts were dried over magnesium sulphate, filtered and evaporated to give an oil which was purified by chromtography on silica gel using ethyl acetate/hexane (1:1, vol/vol) for the elution. After the elution of 1.57 g of starting material, there were obtained 7.51 g (58%) of methyl rac-4,4-ethylenedioxy-1,2,3,4-tetrahydro-2-hydroxy-5,8-dimethoxynaphthalene-2-carboxylate in the form of colourless crystals of melting point 74°-75° C.

Workup

  1. customwas held at -78° C.
  2. stirringwhile stirring for 50 minutes
  3. waitAfter a further 80 minutes
  4. waitAfter 10 minutes
  5. custommost of the tetrahydrofuran was evaporated in vacuo
  6. extractionthe aqueous residue was extracted with five 200 ml portions of ethyl acetate
  7. dry with materialThe combined ethyl acetate extracts were dried over magnesium sulphate
  8. filtrationfiltered
  9. customevaporated
  10. customto give an oil which
  11. customwas purified by chromtography on silica gel
  12. washfor the elution
  13. washAfter the elution of 1.57 g of starting material

Sources & evidence

ORD record
ord-6ed96e3fb94c41f3ac21b967739a83fb
Source dataset
uspto-grants-1985_05
Patent number
US04518784

Reaction notes

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