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

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Reaction Conditions

Reaction Steps

Under a nitrogen atmosphere, a solution of methyl 2-[4-(3,4-dihydro-2H-1-benzopyran-6-yl)-2,5-dimethylthiophen-3-yl]prop-2-enoate (42c) (114 mg, 0.35 mmol) in anhydrous tetrahydrofuran (5 mL) was cooled to −78° C. tert-Butyllithium 1.6M in pentane (0.24 mL, 0.38 mmol) was added dropwise and the reaction mixture was stirred at −78° C. for 20 minutes before being quenched with brine (3 mL). The mixture was extracted with dichloromethane (2×6 mL). The organic layer was dried over sodium sulfate and concentrated in vacuo. The residue was purified by preparative TLC (cyclohexane/ethyl acetate 70/30) to provide the desired product (42d) (102 mg, 0.26 mmol, 76%) as a light yellow oil.

Provenance & Evidence