Ethanol → Ethyl 4-pentenoate

Participants

Reaction Steps

To a solution containing 4-pentenoic acid (20.73 g, 207 mmol) in ethanol (100 mL) and benzene (200 mL) was added H2SO4 (250 μL). The solution was refluxed and monitored by GC (50° C., 1 min to 250° C. at 10° C./min; DB-5; tR of acid 4.4 min, ester 3.8 min). After 15 h, the reaction was complete; about 1/2 of the solvent was removed under reduced pressure and diluted with 150 mL ether. This was extracted with H2O (1×150 mL), saturated NaHCO3 (2×150 mL), H2O (1×150 mL), and brine (1×100 mL). The organic layer was dried over K2CO3, the solvent was removed under water aspirator vacuum, and the residue was distilled to yield ethyl 4-pentenoate, a compound, having the following structure: ##STR11## (20.79 g, 162 mmol, 78%; bp760 144° C.): 1H-NMR (200 MHz, CDCl3) δ 1.25 (t, J=7.2 Hz 3 H, CH3), 2.36 (m, 4 H, CH2CH2), 4.14 (q, J=7.2 Hz, 2 H, OCH2), 4.95-5.13 (m, 2 H, H2C=). 5.81 (m, 1 H, =CH); 13C-NMR (50 MHz, CDCl3) δ 14.2 (CH3), 28.6, 33.5 (C--H2CH2), 115.3 (H2C=), 136.5 (=CH), 172.8 (C=O).

Provenance & Evidence