Water → HCID 13489931, compound

Participants

Reaction Steps

A mixture of 1.0 g (4.3 mmol) of ethyl 4-(2,2-dimethylvinyl)-3-methoxybenzoate, 1.24 g (11.2 mmol); of SeO2, and 0.2 mL of water in 15 mL of dioxane was heated in a 110° C. oil bath for 1.5 h. After cooling to room temperature, the reaction mixture was filtered through Celite (Et2O rinse) to remove excess SeO2. Concentration afforded an orange semisolid residue, which was dissolved in a small amount of toluene and chromatographed on 25 g of silica gel using 30% Et2O/hexane to afford a small amount of a yellow oil (Rf 0.64, Z-isomer) followed by 0.60 g of a yellow solid (Rf 0.56, E-isomer). This solid was rechromatographed on 20 g of silica gel (toluene) to remove colored byproducts (Rf 0.0, 0.38) and to isolate the aldehyde (Rf 0.18), which was submitted to evaporative distillation at 110°- 120° C. (0.005 mm) to afford 0.45 g (42% yield) of very pale yellow solid. The 1H NMR spectrum indicated none of the Z-isomer was present. A sample was purified by crystallization from EtOAc/hexane: white prisms, mp 59°-61° C.; IR (CHCl3) 2840, 1705, 1675, 1410, 1290, 1110, 1010 cm-1 ; 1H NMR (CDCl3) δ 1.42 (t, J=7 Hz, 3, CO2CH2CH3), 2.0 (d, J=0.5 Hz, 3, C=CCH3), 3.95 (s, 3, OCH3), 4.42 (q, J=7 Hz, 2 CO2CH2CH3), 7.3-7.85 (m, 4, C=CH, 3', 5', 6' H), 9.67 (s, 1, CHO); MS calcd for C14H16O4 248.1049, found 248.1058.

Provenance & Evidence