methyl 2-[4-(3,4-dihydro-2H-1-benzopyran-6-yl)-2,5-dimethylthiophen-3-yl]-2-oxoacetate → methyl 2-[4-(3,4-dihydro-2H-1-benzopyran-6-yl)-2,5-dimethylthiophen-3-yl]-2-hydroxypropanoate

HRID 591067Notes

Reaction equation

[O:1]1[C:6]2[CH:7]=[CH:8][C:9]([C:11]3[C:12]([C:18](=[O:23])[C:19]([O:21][CH3:22])=[O:20])=[C:13]([CH3:17])[S:14][C:15]=3[CH3:16])=[CH:10][C:5]=2[CH2:4][CH2:3][CH2:2]1.[CH3:24][Mg]Br>C(OCC)C>[O:1]1[C:6]2[CH:7]=[CH:8][C:9]([C:11]3[C:12]([C:18]([OH:23])([CH3:24])[C:19]([O:21][CH3:22])=[O:20])=[C:13]([CH3:17])[S:14][C:15]=3[CH3:16])=[CH:10][C:5]=2[CH2:4][CH2:3][CH2:2]1

Participants

Conditions

Temperature: 0 °C

Procedure

Under a nitrogen atmosphere, a solution of methyl 2-[4-(3,4-dihydro-2H-1-benzopyran-6-yl)-2,5-dimethylthiophen-3-yl]-2-oxoacetate (360 mg, 1.09 mmol) in anhydrous diethyl ether (5 mL) was cooled to 0° C. Methyl magnesium bromide 3.0 M in diethyl ether (0.73 mL, 2.18 mmol) was added dropwise and the reaction mixture was stirred at 0° C. for 15 minutes, before being quenched with a minimum of water. Ethyl acetate (8 mL) was added and the mixture was dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (cyclohexane/ethyl acetate 100/0 to 80/20) to provide the desired alcohol (42b) (206 mg, 0.59 mmol, 55%) as a colorless oil.

Workup

custombefore being quenched with a minimum of water
additionEthyl acetate (8 mL) was added
dry with materialthe mixture was dried over sodium sulfate
filtrationfiltered
concentrationconcentrated in vacuo
customThe residue was purified by flash chromatography on silica gel (cyclohexane/ethyl acetate 100/0 to 80/20)

Sources & evidence

ORD record: ord-dffe0d7813bc4b3ab93216d4c7bbdba1
Source dataset: uspto-grants-2016_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09238026B2

Reaction notes

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