Boron tribromide → HCID 53305343, compound

HRID 1525748Notes

Reaction equation

HRID 1525748 reaction equation
[CH3:1][C:2]1[CH:7]=[C:6]([O:8]C)[C:5]([CH:10]=[O:11])=[CH:4][C:3]=1[C:12]1[C:21]2[C:16](=[CH:17][CH:18]=[CH:19][C:20]=2[C:22]2[CH:27]=[C:26]([CH:28]=[O:29])[C:25]([O:30]C)=[CH:24][C:23]=2[CH3:32])[CH:15]=[CH:14][CH:13]=1.B(Br)(Br)Br>C(Cl)Cl>[CH3:32][C:23]1[CH:24]=[C:25]([OH:30])[C:26]([CH:28]=[O:29])=[CH:27][C:22]=1[C:20]1[C:21]2[C:16](=[CH:15][CH:14]=[CH:13][C:12]=2[C:3]2[CH:4]=[C:5]([CH:10]=[O:11])[C:6]([OH:8])=[CH:7][C:2]=2[CH3:1])[CH:17]=[CH:18][CH:19]=1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 53305344HCID 53305344, compound

Product 1

HCID 53305343HCID 53305343, compoundYield 77%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 1,8-bis(2′-methyl-4′-methoxy-5′-formylphenyl)naphthalene, 8, (0.78 g, 1.9 mmol) in 35 mL of anhydrous CH2Cl2 at 0° C., BBr3 (11.8 mL, 11.8 mmol) was added dropwise and the mixture was stirred for six hours. The reaction was carefully quenched with isopropyl alcohol followed by addition of water, and extracted with CH2Cl2. The combined organic layers were dried over MgSO4 and concentrated in vacuo. Purification by flash chromatography on silica gel (CH2Cl2:hexanes 20:1) afforded 0.58 g of 5 (1.5 mmol, 77%) as a white solid. The anti/syn-ratio was determined as 20:1 by 1H-NMR spectroscopy. Enantiopure anti-5 was obtained via formation of 9 or 10 as described below and hydrolysis or by asymmetric transformation of the first kind and subsequent hydrolysis (see SI).

Workup

  1. customThe reaction was carefully quenched with isopropyl alcohol
  2. additionfollowed by addition of water
  3. extractionextracted with CH2Cl2
  4. dry with materialThe combined organic layers were dried over MgSO4
  5. concentrationconcentrated in vacuo
  6. customPurification by flash chromatography on silica gel (CH2Cl2:hexanes 20:1)

Sources & evidence

ORD record
ord-eb0e200cba57489392c52ab66056a603
Source dataset
uspto-grants-2015_07
Patent number
US09085511B2

Reaction notes

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