反应详情

Under nitrogen flush, in a 2-necked 100 ml round-bottomed flask equipped with a reflux condenser (flammed for 5 minutes under vacuum and then 3 cycles of N2/vacuum), (1,1-dimethylethyl)(dimethyl){[(3-{[(methyloxy)methyl]oxy}phenyl)methyl]oxy}silane (Intermediate 103, 1.5 g, 5.31 mmol) was dissolved in hexane (20 ml) to give a colourless solution. Butyllithium 1.6N in hexane (4.31 ml, 6.9 mmol) was added dropwise and the reaction mixture was stirred at room temperature. After 2 hours stirring in those conditions, the pale yellow reaction mixture was added to a solution of ethyl chloroformate (1.015 ml, 10.62 mmol) in tetrahydrofuran at −78° C. After 30 min, the reaction was quenched with a 2M aqueous solution of hydrochloric acid while the pH was allowed to reach ˜2 and diluted with 10 ml of ethyl acetate. Two phases were separated and the organic layer was dried over Na2SO4 and evaporated under vacuum affording the crude product as a yellowish oil that was purified by flash chromatography (Biotage system) on silica gel using cyclohexane to cyclohexane/ethyl acetate 8:2 as eluents affording the title compound (1.396 g) as a yellow pale oil.

1. customUnder nitrogen flush, in a 2-necked 100 ml round-bottomed flask
2. customequipped with a reflux condenser (
3. customto give a colourless solution
4. stirringAfter 2 hours stirring in those conditions
5. waitAfter 30 min
6. customthe reaction was quenched with a 2M aqueous solution of hydrochloric acid while the pH
7. additiondiluted with 10 ml of ethyl acetate
8. customTwo phases were separated
9. dry with materialthe organic layer was dried over Na2SO4
10. customevaporated under vacuum
11. customaffording the crude product as a yellowish oil that
12. customwas purified by flash chromatography (Biotage system) on silica gel