Benzoic Acid → (E)-2-t-Butoxycarbonyl-7-phenylhept-2-enyl benzoate

HRID 1107174Notes

Reaction equation

HRID 1107174 reaction equation
N(C(OC(C)C)=O)=NC(OC(C)C)=O.O[CH:16]([C:27](=[CH2:35])[C:28]([O:30][C:31]([CH3:34])([CH3:33])[CH3:32])=[O:29])[CH2:17][CH2:18][CH2:19][CH2:20][C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1.[C:36]([OH:44])(=[O:43])[C:37]1[CH:42]=[CH:41][CH:40]=[CH:39][CH:38]=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>C1COCC1.CCOCC>[C:36]([O:44][CH2:35]/[C:27](/[C:28]([O:30][C:31]([CH3:34])([CH3:33])[CH3:32])=[O:29])=[CH:16]\[CH2:17][CH2:18][CH2:19][CH2:20][C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1)(=[O:43])[C:37]1[CH:42]=[CH:41][CH:40]=[CH:39][CH:38]=1

Participants

7

Reactant 4

HCID 243Benzoic AcidHCID 11776TriphenylphosphineHCID 75555Diisopropyl diazene-1,2-dicarboxylateHCID 18790144t-Butyl 2-(1-hydroxy-5-phenylpentyl)acrylate

Product 1

HCID 69907940(E)-2-t-Butoxycarbonyl-7-phenylhept-2-enyl benzoateYield 82%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

Diisopropyl azodicarboxylate (5 mL, 25 mmol) is added dropwise over 5 minutes to a solution of t-butyl 2-(1-hydroxy-5-phenylpentyl)acrylate (5.59 g, 19.3 mmol), benzoic acid (3 g, 25 mmol) and triphenyl phosphine (6.5 g, 25 mmol) in THF (100 mL) at -55° C. The reaction is maintained between -55 and -50° C. for 45 minutes and then the reaction is allowed to warm to 0° C. The solution is diluted with ether (300 mL) and washed with 1 N NaOH (2×40 mL) and brine (70 mL). The resulting solution is dried (MgSO4) and concentrated in vacuo. The crude reaction product is partially dissolved in 20% ether/petroleum ether and applied to a silica gel column as a slurry. The column is eluted using gradient elution (silica, 10 to 20% ether in petroleum ether) to obtain (E)-2-t-Butoxycarbonyl-7-phenylhept-2-enyl benzoate (6.2 g, 82%): 1H NMR (300 MHz, CDCl3) δ 8.01 (d, J=7.0 Hz, 2H), 7.53-7.49 (m, 1 H), 7.41 (t, J=7.5 Hz, 2H), 7.28-7.23 (m, 2H), 7.20-7.10 (m, 3H), 6.99 (t, J=7.8 Hz, 1H), 5.05 (s, 2H), 2.61 (t, J=7.5 Hz, 2H), 2.36 (q, J=7.5 Hz, 2H), 1.72-1.46 (m, 4H), 1.47 (s, 9H); MS (FAB) m/e 395 (M+H)+.

Workup

  1. temperatureThe reaction is maintained between -55 and -50° C. for 45 minutes
  2. washwashed with 1 N NaOH (2×40 mL) and brine (70 mL)
  3. dry with materialThe resulting solution is dried (MgSO4)
  4. concentrationconcentrated in vacuo
  5. customThe crude reaction product
  6. washThe column is eluted
  7. washgradient elution (silica, 10 to 20% ether in petroleum ether)

Sources & evidence

ORD record
ord-1ebdc7453fe34652a7f7d213f1401545
Source dataset
uspto-grants-2000_05
Patent number
US06057369

Reaction notes

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