Pyridine → HCID 67794398, compound

Participants

Reaction Conditions

Reaction Steps

A solution of ethyl chloroformate (5.42 g, 0.05 mol) in dichloromethane (10 mL) was added dropwise over a 30 minute period to a cold (10° C.) solution of 3-oxo-α-ionol (5.20 g, 0.025 mol, which may be prepared as described by A. J. Aasen, B. Kimland and C. R. Enzell in Acta Chem. Scand., 1973, 27, 2107-2114) and pyridine (3.96 g, 0.05 mol) in dichloromethane (80 mL). The mixture was stirred at 25° C. for 18 hours. Dichloromethane (100 mL) was then added and the mixture washed with 5% phosphoric acid solution (3×100 mL), saturated sodium bicarbonate solution until neutral and dried (sodium sulfate). Evaporation of solvent an chromatography of the residue followed by kugelrohr distillation (50° C. both temp. 0.5 mm) provided 4-(3-hydroxy-1-butenyl)-3,5,5,-trimethyl-2-cyclohexen-1-one ethyl carbonate (2.15 g, GLC purity; 87%) 1H-NMR (CDCl3) δ0.97 (3H,s), 1.05 (3H, s), 1.31 (3H, t, J=7Hz), 1.41 (3H, d, J=7Hz), 1.92 (3H,s) 2.1-2.3 (2H,dd), 2.4-2.7 (1H,m), 4.25 (2H,q, J=7Hz), 5.0-5.4 (1H,m), 5.5-5.8 (2H,m), 5.95 (1H,s); IR (film) vmax 2960, 1750, 1670, 1630, 1470, 1450, 1370, 1260 cm-1 ; MS m/e 280, 224, 190, 175, 134, 108. ##STR7##

Provenance & Evidence