反应详情

温度

-30 °C

A solution of lithium amide (prepared from 3.5 g-atoms of lithium in 500 ml liquid NH2) was stirred at -30° C. while 2-methyl-2-(3-butynyl)-1,3-dioxolane (70.0 g, 0.5 mol) was added thereto dropwise over a 45 minute period. The solution was allowed to stir at -30° C. for 1 hour and subsequently cooled to -60° C.; 1-chloro-3-iodo-propane (103 g, 0.5 mol) then was added dropwise over a 30 minute period. After the addition was completed, the reaction was stirred at -30° C. for 4 hours. Solid NH4Cl (25 g, 0.47 mol) was added and the ammonia allowed to evaporate overnight. Water (200 ml) and ether (300 ml) were added to the solid residue and stirred for 15 minutes. The solution was filtered through infusorial earth (CELITE®) and the layers separated. The aqueous layer was further extracted with ether (2 × 200 ml) and the combined organic layers washed with water, brine, and dried over anhydrous MgSO4. Evaporation of the solvent gave 97 g of 2-methyl-2-(7-chloro-3-heptynyl)-1,3-dioxolane as an orange oil, bp 87°-88° C/ 0.15 mm. Yield: 65 g, 60%. NMR (CDCl3): 1.28(s, 3H); 1.67-2.52(m, 8H); 3.62(s, 2H); and 3.9(s, 4H).

1. additionwas added
2. temperaturesubsequently cooled to -60° C.
3. additionAfter the addition
4. stirringthe reaction was stirred at -30° C. for 4 hours
5. customto evaporate overnight
6. additionWater (200 ml) and ether (300 ml) were added to the solid residue
7. stirringstirred for 15 minutes
8. filtrationThe solution was filtered through infusorial earth (CELITE®)
9. customthe layers separated
10. extractionThe aqueous layer was further extracted with ether (2 × 200 ml)
11. washthe combined organic layers washed with water, brine
12. dry with materialdried over anhydrous MgSO4
13. customEvaporation of the solvent