Diisopropylamine → (+/-)-6-Benzyloxy-2,5,7,8-tetramethylchroman2-acetic acid

HRID 2399074Notes

Reaction equation

HRID 2399074 reaction equation
C(NC(C)C)(C)C.C([Li])CCC.C([N-]C(C)C)(C)C.[Li+].[CH2:21]([O:28][C:29]1[C:30]([CH3:46])=[C:31]2[C:36](=[C:37]([CH3:40])[C:38]=1[CH3:39])[O:35][C@@:34]([CH3:45])([CH2:41][C:42]([OH:44])=[O:43])[CH2:33][CH2:32]2)[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1>O1CCCC1>[CH2:21]([O:28][C:29]1[C:30]([CH3:46])=[C:31]2[C:36](=[C:37]([CH3:40])[C:38]=1[CH3:39])[O:35][C:34]([CH3:45])([CH2:41][C:42]([OH:44])=[O:43])[CH2:33][CH2:32]2)[C:22]1[CH:23]=[CH:24][CH:25]=[CH:26][CH:27]=1

Participants

6

Reactant 4

HCID 7912DiisopropylamineHCID 2724682Lithium diisopropylamideHCID 54154878(R)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-acetic acidHCID 178418339Butyllithium

Product 1

HCID 14368743(+/-)-6-Benzyloxy-2,5,7,8-tetramethylchroman2-acetic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of 11.0 g. of diisopropylamine in 50 ml. of anhydrous tetrahydrofuran at 0° was added 50 ml. of 2N butyllithium solution. To the resultant solution of lithium diisopropylamide was added a solution of 3.54 g. of (R)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-acetic acid in 25 ml. of tetrahydrofuran. The resulting mixture was heated at 50° for 4 hours, acidified with 2N HCI and extracted with ether. The ether solutions were washed with brine, dried (Na2SO4) and stripped of solvent to give (±)-6-benzyloxy-2,5,7,8-tetramethylchroman-2-acetic acid, αD25= ± 0°, m.p. 130° -133°.

Workup

  1. temperatureThe resulting mixture was heated at 50° for 4 hours
  2. extractionextracted with ether
  3. washThe ether solutions were washed with brine
  4. dry with materialdried (Na2SO4)

Sources & evidence

ORD record
ord-a7b668b09c2a4a53a480afabd74ee238
Source dataset
uspto-grants-1977_05
Patent number
US04026907

Reaction notes

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