Diethyl Ether → 2,2-Dimethyl-4-(1-naphthyl)-7-chromanol

HRID 2163358Notes

Reaction equation

HRID 2163358 reaction equation
[CH3:1][Li].[OH:3][C:4]1C=C2[C:7]([CH:8]([C:15]3[C:24]4[C:19](=[CH:20][CH:21]=[CH:22][CH:23]=4)[CH:18]=[CH:17][CH:16]=3)[CH2:9]C(=O)O2)=[CH:6][CH:5]=1.[CH3:25][CH2:26][O:27][CH2:28][CH3:29]>C(O)(=O)C>[CH3:25][C:26]1([CH3:1])[CH2:9][CH:8]([C:15]2[C:24]3[C:19](=[CH:20][CH:21]=[CH:22][CH:23]=3)[CH:18]=[CH:17][CH:16]=2)[C:7]2[C:28](=[CH:29][C:4]([OH:3])=[CH:5][CH:6]=2)[O:27]1

Participants

5

Reactant 3

HCID 3283Diethyl EtherHCID 205705223,4-Dihydro-7-hydroxy-4-(1-naphthyl)coumarinHCID 178418348HCID 178418348, compound

Product 1

HCID 205705012,2-Dimethyl-4-(1-naphthyl)-7-chromanol

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To a stirred solution of methyl-lithium in ether (120 ml., 1.9M solution) at room temperature was added over 0.5 hours finely powdered 3,4-dihydro-7-hydroxy-4-(1-napthyl) coumarin (14.5g, 0.05 moles). After refluxing for 1 hour a purple solid precipitated out of solution and the reaction mixture was allowed to cool, acidified with dilute hydrochloric acid and extracted with ether (3x). The combined ether extracts were dried and removal of solvent gave a dark coloured oil which was refluxed overnight in glacial acetic acid. The glacial acetic acid was removed in vacuo and the residue dissolved in ether, washed with water, saturated sodium bicarbonate solution and dried. Removal of solvent gave an extremely viscous oil, column chromatography of which on silica, eluting with 40-60° petrol: ether (gradually increasing concentration of ether) gave the required chroman as a low melting pale yellow solid (9.4g., 76%).

Workup

  1. temperatureAfter refluxing for 1 hour a purple solid
  2. customprecipitated out of solution
  3. temperatureto cool
  4. extractionextracted with ether (3x)
  5. dry with materialThe combined ether extracts were dried
  6. customremoval of solvent
  7. customgave a dark coloured oil which
  8. customThe glacial acetic acid was removed in vacuo
  9. dissolutionthe residue dissolved in ether
  10. washwashed with water, saturated sodium bicarbonate solution
  11. customdried
  12. customRemoval of solvent
  13. customgave an extremely viscous oil, column chromatography of which on silica
  14. washeluting with 40-60° petrol
  15. temperatureether (gradually increasing concentration of ether)

Sources & evidence

ORD record
ord-47d6fddaec2a4649b7a95e2395b7511c
Source dataset
uspto-grants-1979_01
Patent number
US04133883

Reaction notes

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