Acetaldehyde → Methyl 2-ethylidenehexanoate

Temperature

-30 °C

To 2-(diethylphosphono)hexanoic acid methyl ester (53.2 g, 0.2M) in dry tetrahydrofuran (300 ml) was added sodium hydride (5.3 g, 0.22M) under an atmosphere of argon at 0° C. with continuous stirring. The reaction was allowed to warm to room temperature over 1 hour when the evolution of hydrogen had ceased. The reaction was then cooled to -30° C. and acetaldehyde (30 g, 0.66M) added dropwise to the continuously stirred solution over 10 minutes. The reaction was allowed to warm to 20° C. over 16 h and then concentrated in vacuo to a gum which was dissolved in ether. The etherial solution was washed with aqueous saturated sodium hydrogen carbonate, dried over sodium sulphate and concentrated in vacuo. Vacuum distillation of the resulting gum afforded E and Z 2-(butyl)-but-2-enoic acid methyl ester (7.8 g) B.p. 50°-60° C. at 0.8 mm Hg (Found: C, 65.0; H, 10.1 C9H16O 2 +0.5H2O requires: C, 65.4; H, 10.4%); δ(CDCl3) 0.84 (3H, t, J=8 Hz, CH3CH2); 1.34 (4H, m, 2×CH2); 1.8 and 1.96 (3H each d, each J=7 Hz, CH3CH); 2.32 (2H, m, CH2 --C); 3.72 and 3.74 (3H, each s, CH3O); 5.96 and 6.84 (1H, each q, each J=7 Hz, CH).

1. temperatureto warm to 20° C. over 16 h
2. concentrationconcentrated in vacuo to a gum which
3. dissolutionwas dissolved in ether
4. washThe etherial solution was washed with aqueous saturated sodium hydrogen carbonate
5. dry with materialdried over sodium sulphate
6. concentrationconcentrated in vacuo
7. distillationVacuum distillation of the resulting gum

ORD record

ord-c9f1e99bc96a435980d14db4fa42f83a

Source dataset

uspto-grants-1987_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04681966