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 (1.3 g, 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 1.0N 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 (MH30 ); 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 1.0N 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