No abstract

A novel, convenient synthetic method of 5‐atyl‐2,2‐dimethyl‐3(2H)‐furanones (aryl = C6H5, 2‐CH3C6H4, 3‐CH3C6H4, 4‐CH3C6H4, 2‐CIC6H4, 4‐CIC6H4, 2,4‐Cl2C6H3) is described. It involves the Claisen‐Schmidt condensation (potassium hydroxide/ethanol) of aromatic aldehydes with 3‐hydroxy‐3‐methyl‐2‐butanone to give enones, whose bromination followed by alkaline hydrolysis (sodium hydroxide/ethanol) affords 3(2H)‐furanone derivatives in 54–64% overall yields. The procedure is also applicable to nicotinaldehyde and furfural, although the yields are not satisfactory.

No abstract

The aromatic aldehydes (I) are coupled with 3‐hydroxy‐3‐methyl‐2‐butanone (II) to produce the vinyl ketones (III).

The reaction of the aromatic aldehydes (I) with the chloroketone (II) in 14% ethanolic KOH affords the lactones (III) as major or exclusive products.