4-Bromotoluene → (2S)-1,1-Bis(4-methylphenyl)propane-1,2-diol

HRID 1723069Notes

Reaction equation

HRID 1723069 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([CH3:8])=[CH:4][CH:3]=1.[CH2:9]([Li])[CH2:10][CH2:11][CH3:12].C(OCC)(=O)[C@H](C)O.[C:22]([O-:25])(=O)[CH3:23].[NH4+].[O:27]1[CH2:31][CH2:30][CH2:29][CH2:28]1>CCOCC>[CH3:12][C:11]1[CH:31]=[CH:30][C:29]([C:28]([C:2]2[CH:7]=[CH:6][C:5]([CH3:8])=[CH:4][CH:3]=2)([OH:27])[C@@H:22]([OH:25])[CH3:23])=[CH:9][CH:10]=1

Participants

7

Reactant 5

HCID 78054-BromotolueneHCID 8028Tetrahydrofuran2×HCID 92831(L)-ethyl lactateHCID 517165Ammonium AcetateHCID 178418339Butyllithium

Product 1

HCID 13147839(2S)-1,1-Bis(4-methylphenyl)propane-1,2-diol

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

Part A. A solution of 4-bromotoluene (53.0 g, 0.31 mole) in tetrahydrofuran (400 mL) was stirred at -75° and treated dropwise with n-butyllithium (1.6 M in hexane; 194 mL, 0.31 mole). After stirring for an additional 20 minutes, (S)-ethyl lactate (11.8 g, 0.1 mole) was added dropwise as a solution in tetrahydrofuran (20 mL). The reaction was stirred for three hours, during which time the temperature was allowed to rise to room temperature. Saturated aqueous ammonium acetate was added, after which the reaction mixture was diluted with ether, washed with water and brine, dried (MgSO4) and concentrated under reduced pressure. (S)-1,1-bis(4-methyl-phenyl)-1,2-propanediol (27 g) was isolated as a pale yellow solid, and was used without further purification. NMR(CDCl3) 7.44(2H,d,J=8 Hz) 7.28(2H,d,J=8 Hz) 7.13(2H,d,J=8 Hz) 7.06(2H,d,J=8 Hz) 4.74(1H,q,J=6 Hz) 2.97(1H,broad) 2.29(6H,2s) 1.90(1H,braod s) 1.10(3H,d,J=6 Hz).

Workup

  1. stirringThe reaction was stirred for three hours, during which time the temperature
  2. customto rise to room temperature
  3. washwashed with water and brine
  4. dry with materialdried (MgSO4)
  5. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-1534f8ad5d3e486faadcc1adbca15793
Source dataset
uspto-grants-1989_08
Patent number
US04859693

Reaction notes

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