Phosphoric Acid → HCID 13050820, compound

Participants

Reaction Steps

A buffer solution was prepared by dissolving potassium secondary phosphate (4 g) in water (800 ml) and adjusting the pH value to 7.5 (25° C.) with phosphoric acid. In a reaction vessel, 5-methyl-2-furyl-(α-methylallyl)-carbinol (20 g) and the entire amount of the buffer solution as prepared above were charged, and the temperature was elevated up to 180° C. in 55 minutes while stirring. The mixture was stirred at the same temperature for 5 hours, the inner pressure at this time being 9 kg/cm2. After ice-cooling, sodium chloride (100 g) was added thereto, and the mixture was extracted with methyl isobutyl ketone (200 ml) four times. The extract was concentrated at 60° C. under reduced pressure to remove methyl isobutyl ketone, and the resultant residue was subjected to distillation (112°-117° C./0.3 mmHg) to obtain 2-(α-methylallyl)-3-methyl-4-hydroxy-2-cyclopentenone (15.3 g). Yield, 76.5%. NMR spectrum (CDCl3 internal standard; TMS, δppm, 60 MHz): 5.99 (complex m, 1H, ##STR8## 5.08 (m, 1H, ##STR9## 4.84 (m, 1H, ##STR10## 4.63 (broad d, 1H, 4-H); 3.33 (m, 2H, 4-OH and ##STR11## 2.73 (dd, 1H, 5-H); 2.21 (dd, 1H, 5-H); 2.08 (s, 3H, 3-CH3); 1.21 (d, 3H, ##STR12##

Provenance & Evidence