Diethyl Malonate → Diethyl 3-(benzyloxy)cyclobutane-1,1-dicarboxylate

Participants

Reaction Steps

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 (Step 2). The mixture was heated at reflux for 44 hr, cooled to room 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) δ 1.23 (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).

Provenance & Evidence