反应详情

温度

-5 °C

A mixture of 5,6-dihydro-7-hydroxy-5,5-dimethyl-7H-thieno [3,2-b]pyran (1.3g, 7.06 mmol), p-toluenesulfonic acid (0.11 g, 0.58 mmol) and ground molecular sieves (1.3 g) was stirred at -5° C. for 1.5 h. The mixture was washed with 1.0 N aqueous sodium hydroxide and dried over magnesium sulfate. The solvent was evaporated in vacuo to give the product, 1.17 g (99%), as a red oil: IR (neat): 2976, 1504 and 1531 cm-1 ; MS: m/z 167 (MH+); 1H NMR (CDCl3): δ1.45 (s, 6H), 5.27 (d, J=9.8 Hz, 1H), 6.30 (d, J=9.8 Hz, 1H), 6.60 (d, J=5.3 Hz, 1H) and 6.99 (d, J=5.3 Hz, 1H). This oil was used without further purification in the next step.

1. washThe mixture was washed with 1.0 N aqueous sodium hydroxide
2. dry with materialdried over magnesium sulfate
3. customThe solvent was evaporated in vacuo
4. customto give the product, 1.17 g (99%)
5. customThis oil was used without further purification in the next step