Ammonium Chloride → Ethyl (2e,4e,6e,10z,13z,16z,19z)-3-methyl-docosa-2,4,6,10,13,16,19-heptaenoate

HRID 1925676Notes

Reaction equation

[CH3:1][CH2:2][O:3][C:4](/[CH:6]=[C:7](/[CH2:9]P(OCC)(OCC)=O)\[CH3:8])=[O:5].[CH2:18]1[CH2:22]O[CH2:20][CH2:19]1.CN1C(=O)N(C)[CH2:27][CH2:26][CH2:25]1.[Li][CH2:33][CH2:34][CH2:35][CH3:36].[NH4+].[Cl-]>C1COCC1>[CH3:8]/[C:7](/[CH:9]=[CH:20]/[CH:19]=[CH:18]/[CH2:22][CH2:25]/[CH:26]=[CH:27]\[CH2:36]/[CH:35]=[CH:34]\[CH2:33]/[CH:22]=[CH:18]\[CH2:19]/[CH:20]=[CH:25]\[CH2:26][CH3:27])=[CH:6]\[C:4]([O:3][CH2:2][CH3:1])=[O:5]

Participants

Conditions

Temperature: 0 °C

Procedure

A solution of triethyl 3-methyl-4-phosphono-2-butenoate (485 μl, 1.96 mmol) in a 5:1 mixture of anhydrous THF-DMPU (20 ml) was cooled to 0° C., and n-BuLi (2.5 M in hexane, 760 μl, 1.90 mmol) was added. The mixture was stirred for 0° C. for 20 min and then cooled to −78° C. A solution of (2E,6Z,9Z,12Z,15Z)-octadeca-2,4,6,10,13,16,19-pentaenal in THF (2 ml) was added, and the reaction mixture was stirred at −78° C. for an hour. The mixture was then allowed to warm to 0° C. during an hour. Then a saturated aqueous NH4Cl solution was added and the phases were separated. The aqueous phase was extracted with ethyl acetate. The combined organic phases were washed with water and dried (MgSO4). Evaporation of the solvents under reduced pressure followed by flash chromatography on silica:gel (95:5 hexane-EtOAc) gave the ester (120 mg).

Workup

temperaturecooled to −78° C
stirringthe reaction mixture was stirred at −78° C. for an hour
temperatureto warm to 0° C. during an hour
customthe phases were separated
extractionThe aqueous phase was extracted with ethyl acetate
washThe combined organic phases were washed with water
dry with materialdried (MgSO4)
customEvaporation of the solvents under reduced pressure

Sources & evidence

ORD record: ord-9bb8b2abc1ea4bf18d40aba37b7a0def
Source dataset: uspto-grants-2012_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08178708B2

Reaction notes

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