Synthesis
Methyl ethanoate (4.5 g, 50 mmol) was added slowly and dropwise to a stirred slurry of anhydrous ether (40 mL) of sodium hydride (2.2 g, 55 mmol) at room temperature (rt). The reaction mixture was stirred continuously for 14 h at room temperature and then concentrated under vacuum. Subsequently, a solution of methyl acrylate (5.2 g, 55 mmol) in DMSO (20 mL) was added to the resulting solid at 0 °C and the mixture was stirred for 15 minutes. After removing the cooling bath, stirring was continued for 45 min. The reaction mixture was poured into 5% H2SO4 (60 mL) and extracted with ether (150 mL). The organic layer was dried, concentrated, and purified by column chromatography to yield methyl 4-oxotetrahydrofuran-3-carboxylate 1.7 g (24% yield).1H NMR (CDCl3) data were as follows: δ 4.51-4.40 (m, 2H), 4.03 (q, J = 8.1 Hz, 2H), 3.80 (s, 3H), 3.54 (t, J = 8.1 Hz 1H).
References
[1] Journal of Medicinal Chemistry, 2018, vol. 61, # 5, p. 2124 - 2130
[2] Bioorganic and Medicinal Chemistry Letters, 2008, vol. 18, # 3, p. 1124 - 1130
[3] Patent: WO2008/21456, 2008, A2. Location in patent: Page/Page column 32
[4] Patent: WO2018/137573, 2018, A1. Location in patent: Page/Page column 104
[5] Tetrahedron Letters, 1989, vol. 30, # 45, p. 6129 - 6132
