反应详情

Dry Mg (1.15 g) under dry N2 in a flask is covered with THF (10 ml) and a crystal of I2 added. 5 ml of a solution of 4-bromobenzaldehyde ethylene acetal (10.0 g) in THF (40 ml) is added and kept until it becomes warm, when it is cooled to 15°, and the remainder of the acetal added over 15 minutes, then stirred for an additional 1 hour. A mixture of ground lithium chloride (0.35 g) and copper (I) chloride (0.70 g) dissolved in THF is prepared, treated with Z-1,3-dichloropropene (8.0 g) produced by spinning band distillation of commercially available 1,3-dichloropropene comprising a mixture of the E and Z isomers and cooled to -20°. The above Grignard solution (under moisture excluding conditions) is then added to this solution during 5 minutes, and allowed to warm to 20° with stirring for 16 hours. Saturated aqueous ammonium chloride is added and the organic layer evaporated under reduced pressure to a small residue, which is dissolved in THF (100 ml), cooled to -10°, treated with 3N HCl (50 ml), then stirred at 20° for 1 hour. The product is partitioned between ether and water, and the ether layer washed with saturated aqueous NaHCO3, H2O, saturated aqueous NaCl, dried (MgSO4) and the residue chromatographed on florisil. The fraction eluted by 15 % diethyl ether in petroleum ether bp 60°-80° C. is collected and purified by preparative HPLC. Yield 1.12 g (14%) nD20 1.5655.

1. temperaturebecomes warm
2. temperaturewhen it is cooled to 15°
3. customis prepared
4. customproduced
5. distillationband distillation of commercially available 1,3-dichloropropene comprising
6. additiona mixture of the E and Z isomers
7. temperaturecooled to -20°
8. additionThe above Grignard solution (under moisture excluding conditions) is then added to this solution during 5 minutes
9. temperatureto warm to 20°
10. stirringwith stirring for 16 hours
11. additionSaturated aqueous ammonium chloride is added
12. customthe organic layer evaporated under reduced pressure to a small residue, which
13. dissolutionis dissolved in THF (100 ml)
14. temperaturecooled to -10°
15. additiontreated with 3N HCl (50 ml)
16. stirringstirred at 20° for 1 hour
17. customThe product is partitioned between ether and water
18. washthe ether layer washed with saturated aqueous NaHCO3, H2O, saturated aqueous NaCl
19. dry with materialdried (MgSO4)
20. customthe residue chromatographed on florisil
21. washThe fraction eluted by 15 % diethyl ether in petroleum ether bp 60°-80° C.
22. customis collected
23. custompurified by preparative HPLC