反应详情

To solution of crude 3-(2,2-dibromoethenyl)-2,5-dimethoxy-tetrahydrofuran (1.78 g, 5.64 mmol) in ether (30 mL) at −78° C. was added n-butyllithium (9.02 mL of 1.25 M in hex). After 1 hour at −78° C., tributyltin chloride (1.68 mL, 6.20 mmol) was added, and the mixture was allowed to warm to ambient temperature. After 16 hours, ether (35 mL) and saturated aqueous NH4Cl (30 mL) were added. The organic layer was separated, washed with saturated aqueous NH4Cl (30 mL), H2O (25 mL), and saturated aqueous NaHCO3 (25 mL), dried over K2CO3, and evaporated to give an orange oil, which was purified via flash column chromatography with 2% MTBE/hex to furnish 1.92 g (77%) of 2,5-dimethoxy-3-(2-tributylstannylethynyl)-tetrahydrofuran as a colorless oil. A mixture of diastereomers was evident in the 1H NMR spectrum, which was used immediately without further purification. IR: 2923, 1456, 1374, 1215, 1105, 1017, 967 cm−1. Anal. Calculated for C20H38O3Sn: C, 53.96; H, 8.60. Found: C, 54.21; H, 8.66.

1. waitAfter 16 hours
2. customThe organic layer was separated
3. washwashed with saturated aqueous NH4Cl (30 mL), H2O (25 mL), and saturated aqueous NaHCO3 (25 mL)
4. dry with materialdried over K2CO3
5. customevaporated
6. customto give an orange oil, which
7. customwas purified via flash column chromatography with 2% MTBE/hex