Potassium Carbonate → HCID 502055, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 7-propionate 7a (0.83 g, 3.0 mmol) in 2-butanone (40 mL) and DMF (4 mL) were added tetrabutylammonium iodide (1.11 g, 3 rnmol), K2CO3 (1.04 g, 7.5 mmol), and 3-chloro-3-methyl-1-butyne (1.11 g, 3 mmol). The reaction mixture was heated at 60° C. for 1 h before ZnCl2 (3.9 mL of 1.0 M solution in ether, 3.9 mmol) was added. The temperature was then raised to 70° C. and maintained at that temperature for 21 h. The reaction mixture was cooled to room temperature and quenched with saturated aqueous NH4Cl (100 mL). The mixture was extracted with EtOAc (100 mL×2) and the combined organic layers were washed with brine (100 mL) and dried over Na2SO4. Evaporation of the solvent gave the crude product (1.9 g). After column chromtographic purification, 280 mg (27.1% yield) of the desired product 5a was obtained as a waxy solid. 1H NMR (DMSO-d6) 1.00 (3H, t, J=7.2 Hz), 1.16 (3H, t, J=7.5 Hz); 1.47 (6H, s), 1.61 (2H, m), 2.71 (2H, q, J=7.5 Hz), 2.89 (2H, t, J=7.8), 5.84 (1H, d, J=9.9 Hz), 6.17 (1H, s), 6.41 (1H, d, J=10.2 Hz); 13C NMR (DMSO-d6) 8.6, 13.7, 22.8, 26.6, 27.2, 37.4, 78.3, 103.6, 107.2, 110.8, 113.4, 115.5, 130.1, 148.5, 151.4, 154.4, 156.9, 159.3, 172.2; IR 1767 (s and sharp), 1723 (s and sharp), 1616 (s and sharp) cm−1; MS m/e 343 (M+1); Anal. Calcd. for C20H22O5: C, 70.16; H, 6.47. Found: C, 70.37; H, 6.51.

Provenance & Evidence