반응 #2721

반응 방정식

2,2-dimethyl-4(2-methyl-thien-5-yl)-thiochrom-3-en-6-al

Compound U

2,2-dimethyl-4(2-methyl-thien-5-yl)-thiochrom-3-en-6-al

THF

ethyl 4-(diethoxyphosphoryl-3,3-dimethoxypropyl)benzoate

Compound D

ethyl 4-(diethoxyphosphoryl-3,3-dimethoxypropyl)benzoate

lithium diisopropylamide

THF

THF

→

product E

ethyl 4-[1-(2,2-dimethoxyethyl)-2-{1(tol-4-yl)3,4-dihydro-4,4-dimethyl-naphthalen-7-yl}-(E)-ethenyl]-benzoate

반응 조건

후처리

1. 1
   기타was recooled to -78° C.
2. 2
   온도The reaction mixture was gradually warmed to -10° C. over 2 hours
3. 3
   기타Then the reaction was quenched
4. 4
   workup.ADDITIONby adding water (5 mL) and ethyl acetate (70 mL)
5. 5
   세척The organic layer was washed with brine (10 mL)
6. 6
   기타dried
7. 7
   기타the solvent was removed by distillation

실험 절차

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.

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