Title: The Formic Acid Rearrangement of 3,4-Dimethyl-1-pentyn-3-ol and 3-Isopropyl-4-methyl-1-pentyn-3-ol
Abstract: Abstract The behavior of 3,4-dimethyl-1-pentyn-3-ol (II) and 3-isopropyl-4-methyl-1-pentyn-3-ol (III) toward formic acid was investigated. The carbinols, as in the previous report, were chosen as model ones in which the tertiary carbon atom is adjacent to the carbon atom carrying the hydroxyl group. Both carbinols gave a significant quantity of the respective aldehydes. These aldehydes were easily isolated on simple distillation. II gave 3,4-dimethyl-3-penten-2-one (IIa) in 45% yield and 3,4-dimethyl-2-pentenal (lib), a new aldehyde, in 5% yield. Ill gave 3-isopropyl-4-methyl-3-penten-2-one (IlIa) in 55% yield and 3-isopropyl-4-methyl-2-pentenal (IIIb) in 6% yield. These carbonyl compounds were characterized. IIIb was hydrogenated to give 3-isopropyl-4-methylpentanal (IV) as the 2,4-dinitrophenylhydrazone.