反应详情

To a stirred slurry of 4.6 g (0.19 mol) sodium hydride in 115 mL of dry dioxane was added dropwise 30.4 (0.10 mol) of diethyl malonate over a 30 min period. After this addition was complete, 50.0 g (0.19 mol) of 1-chloro-2-benzyloxy-3-bromopropane 3 was added dropwise in 30 min (St mixture was heated at reflux for 44 hr, cooled to room ##STR5## temperature, and 4.6 g (0.19 mol) of sodium hydride in 50 mL of dioxane was added in portions. The mixture was heated at reflux for an additional 120 hr. The solvent was partially removed under reduced pressure and the mixture was treated with 100 mL of water. The organic layer was extracted into ether. The ether extracts were dried and concentrated and the residue was distilled under reduced pressure. Distillation through a 12-in Vigreux column yielded 49.0 g (85%) of diethyl 3-benzyloxycyclobutane-1, 1-dicarboxylate 4 bp 174°-176° C. (0.9 mm); 1H NMR(CDCl3) δ1.23 (t, J=7 Hz, 6H, CH3), 4.0-4.7 (m, 1H OCH), 4.34 (s, 2H OCH2), 4.13 (q, J=7 Hz, 4H, OCOCH2), 7.23 (s, 5H, phenyl).

1. additionAfter this addition
2. temperaturewas heated
3. temperatureat reflux for 44 hr
4. additionwas added in portions
5. temperatureThe mixture was heated
6. temperatureat reflux for an additional 120 hr
7. customThe solvent was partially removed under reduced pressure
8. additionthe mixture was treated with 100 mL of water
9. extractionThe organic layer was extracted into ether
10. dry with materialThe ether extracts were dried
11. concentrationconcentrated
12. distillationthe residue was distilled under reduced pressure
13. distillationDistillation through a 12-in Vigreux column