تفاعل #2721
ord-3162245e48fc4356bfa767714f3ab8d2
معادلة التفاعل
المتفاعلات
الكواشف
ظروف التفاعل
المعالجة
- 1أخرىwas recooled to -78° C.
- 2درجة الحرارةThe reaction mixture was gradually warmed to -10° C. over 2 hours
- 3أخرىThen the reaction was quenched
- 4workup.ADDITIONby adding water (5 mL) and ethyl acetate (70 mL)
- 5غسيلThe organic layer was washed with brine (10 mL)
- 6أخرىdried
- 7أخرىthe solvent was removed by distillation
الإجراء التجريبي
To a cold (-78° C.) solution of ethyl 4-(diethoxyphosphoryl-3,3-dimethoxypropyl)benzoate (Compound D, 500 mg, 1.29 mmol) in THF (2.5 mL) was added fleshly prepared lithium diisopropylamide in THF(1.5 mmol). The mixture was allowed to warm to -5° C. over a period of 1 hour and 40 minutes. The reaction mixture was recooled to -78° C. and 2,2-dimethyl-4(2-methyl-thien-5-yl)-thiochrom-3-en-6-al (Compound U, 180 mg, 0.58 mmol) in THF (2 mL) was added. The reaction mixture was gradually warmed to -10° C. over 2 hours. Then the reaction was quenched by adding water (5 mL) and ethyl acetate (70 mL). The organic layer was washed with brine (10 mL) dried and the solvent was removed by distillation. The product E and Z isomers were isolated by column chromatography. The required E (minor) isomer (45 mg) was dissolved in dichloromethane (5 mL) and cooled to -78° C. To this solution SnCl4 (110 mg, 0.42 mmol) in dichloromethane (1 mL) was added dropwise, the reaction mixture was gradually warmed to -30° C. over 30 min. The reaction was quenched by adding ethanol (0.5 mL), water (5 mL) and ethyl acetate (75 mL). The organic layer was washed with brine (10 mL), dried and the solvent was removed by distillation. The title compound was isolated as a white solid after column chromatography.