Pyridine → Beta-Carotene

HRID 2078526Notes

Reaction equation

HRID 2078526 reaction equation
C1(S([CH:10]([C:61]2[C:66]([CH3:68])([CH3:67])[CH2:65][CH2:64][CH2:63][C:62]=2[CH3:69])[CH:11](O)[C:12]([CH3:59])=[CH:13][CH2:14][CH2:15][C:16]([CH3:58])=[CH:17][CH:18](S(C2C=CC=CC=2)(=O)=O)[CH2:19][CH:20]=[C:21]([CH3:48])[CH2:22][CH2:23][CH:24]=[C:25]([CH3:47])[CH:26](O)[CH:27](S(C2C=CC=CC=2)(=O)=O)[C:28]2[C:33]([CH3:35])([CH3:34])[CH2:32][CH2:31][CH2:30][C:29]=2[CH3:36])(=O)=O)C=CC=CC=1.N1C=CC=CC=1.P(Br)(Br)Br>C(Cl)Cl>[CH3:69][C:62]1[CH2:63][CH2:64][CH2:65][C:66]([CH3:67])([CH3:68])[C:61]=1/[CH:10]=[CH:11]/[C:12](/[CH3:59])=[CH:13]/[CH:14]=[CH:15]/[C:16](/[CH3:58])=[CH:17]/[CH:18]=[CH:19]/[CH:20]=[C:21](\[CH3:48])/[CH:22]=[CH:23]/[CH:24]=[C:25](\[CH3:47])/[CH:26]=[CH:27]/[C:28]1[C:33]([CH3:35])([CH3:34])[CH2:32][CH2:31][CH2:30][C:29]=1[CH3:36]

Participants

5

Reactant 3

HCID 1049PyridineHCID 24614Phosphorus tribromideHCID 866374611,9,18-Tris(benzenesulfonyl)-3,7,12,16-tetramethyl-1,18-bis(2,6,6-trimethyl-1-cycl ohexen-1-yl)-3,7,11,15-octadecatetraene-2,17-diol

Product 1

HCID 5280489Beta-Carotene

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
0 °C

Procedure

To a stirred solution of the C40 diol compound (O) (0.13 g, 0.15 mmol) in CH2Cl2 (5 mL) at 0° C. were added pyridine (0.054 mL, 0.60 mmol) and PBr3 (0.011 mL, 0.12 mmol). The mixture was stirred at 0° C. for 40 min, diluted with CH2Cl2 (20 mL), washed with 1 M HCl solution (10 mL×3), dried over anhydrous MgSO4, filtered, and concentrated under reduced pressure to give the di-bromination product (P-1) (0.17 g, 0.15 mmol) in 100% crude yield. This compound was not purified and directly utilized in the elimination reaction to produce β-carotene (see Example 15-A).

Workup

  1. washwashed with 1 M HCl solution (10 mL×3)
  2. dry with materialdried over anhydrous MgSO4
  3. filtrationfiltered
  4. concentrationconcentrated under reduced pressure
  5. customto give the di-bromination product (P-1) (0.17 g, 0.15 mmol) in 100% crude yield
  6. customThis compound was not purified
  7. customdirectly utilized in the elimination reaction

Sources & evidence

ORD record
ord-469da37769264cdeb611b1563a710e54
Source dataset
uspto-grants-2011_04
Patent number
US07928266B2

Reaction notes

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