Water → 2-But-3-enyl-2-thiophen-2-yl-hex-5-enoic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

Ethyl 2-(thiophen-2-yl)acetate (2.35 g) was dissolved in tetrahydrofuran (30 mL) and cooled to −78° C. Lithium bis(trimethylsilyl)amide (2.31 g) in THF (1M solution, 13.8 mL) was added and the solution was stirred for 30 minutes. 4-Bromo-but-1-ene (1.4 mL) was added and the reaction mixture was allowed to warm to room temperature and stirred for 1 hour. The reaction mixture was re-cooled to −78° C. and lithium bis(trimethylsilyl)amide (2.31 g) in THF (1M solution, 13.8 mL) was added and the solution was stirred for 30 minutes. 4-Bromo-but-1-ene (1.4 mL) was added and the reaction mixture was allowed to warm to room temperature and stand overnight. HPLC-MS analysis indicated that the reaction was incomplete so the reaction was again cooled to −78° C. and further aliquots of lithium bis(trimethylsilyl)amide (1M solution, 10 mL) and 4-bromo-but-1-ene (1.0 mL) were added following the procedure outlined above. After stirring for a further 2 hours, water (30 mL) was added and the reaction was extracted with diethyl ether (2×60 mL). The combined organic extracts were dried (MgSO4) and evaporated. The resulting oil was purified by column chromatography on silica eluting with ethyl acetate/isohexane (1/99) afford the sub-titled compound (3.18 g).

Provenance & Evidence