Methanol → methyl (Z)-5-(2,5-dimethoxy-3,4,6-trimethylphenyl)-3-methyl-2-pentenoate

HRID 1195475Notes

Reaction equation

[CH3:1][Li].[CH3:3][O:4][C:5]1[C:10]([CH3:11])=[C:9]([CH3:12])[C:8]([O:13][CH3:14])=[C:7]([CH3:15])[C:6]=1[CH2:16][CH2:17][C:18]#[C:19][C:20]([O:22][CH3:23])=[O:21].CO.[Cl-].[NH4+]>CCOCC.C1COCC1.[Cu]I>[CH3:3][O:4][C:5]1[C:10]([CH3:11])=[C:9]([CH3:12])[C:8]([O:13][CH3:14])=[C:7]([CH3:15])[C:6]=1[CH2:16][CH2:17]/[C:18](/[CH3:1])=[CH:19]\[C:20]([O:22][CH3:23])=[O:21]

Participants

Conditions

Temperature: -78 °C

Procedure

A solution of lithium dimethylcuprate (prepared from 0.97 g (5.1 mmol) of copper-(I) iodide and 6.4 ml of a 1.6M ethereal methyllithium solution) in ether (30 ml) was cooled to -78° C. and treated dropwise with a solution of methyl 5-(2,5-dimethoxy-3,4,6-trimethylphenyl)-2-pentynoate (1 g; 3.4 mmol) in THF (10 ml). The mixture was stirred at -78° C. for 90 minutes, treated with 0.5 ml of methanol, warmed to room temperature and treated with saturated ammonium chloride solution. The mixture was extracted twice with ether and the combined extracts were washed with water and dried. The remaining residue was purified on silica gel with hexane/ethyl acetate (95:5), yielding 0.81 g of crystalline methyl (Z)-5-(2,5-dimethoxy-3,4,6-trimethylphenyl)-3-methyl-2-pentenoate. M.P. 87.5°-89° C.

Workup

temperaturewarmed to room temperature
extractionThe mixture was extracted twice with ether
washthe combined extracts were washed with water
customdried
customThe remaining residue was purified on silica gel with hexane/ethyl acetate (95:5)

Sources & evidence

ORD record: ord-b31d2bbffac54b5295e20ef7dc4a68b7
Source dataset: uspto-grants-1992_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05110955

Reaction notes

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