Réaction #95555

Équation de réaction

1,1-dimethoxy-oct-7-yne

lithium

ammonia

lithium amide

1,1-dimethoxy-6-iodohexane

→

tetradec-7-yn-1,14-dial dimethylacetal

Rendement 84.5%

Solvants

Dimethyl-sulfoxide

—

liquid

Conditions de réaction

Traitement

1. 1
   Autreabove gave an oil
2. 2
   Autrefrom which low-boiling impurities were removed
3. 3
   Températureby heating at 100°/0.05 Torr

Mode opératoire

To a stirred suspension of lithium amide, prepared from 1.45 g (0.21 atom) of lithium in ca. 200 ml of liquid ammonia was added 30.6 g (0.18 Mole) of 1,1-dimethoxy-oct-7-yne over a period of 10 min. Dimethyl-sulfoxide (100 ml) was then added, followed by 62.5 g (0.23 Mole) of 1,1-dimethoxy-6-iodohexane within 10 min. Work-up as above gave an oil, from which low-boiling impurities were removed by heating at 100°/0.05 Torr. Crude tetradec-7-yn-1,14-dial dimethylacetal (40.8 g, 72% yield) was used without further purification. A sample was submitted to a rapid distillation: b.p. 140°/0.05 Torr.--IR: 1125, 1070, 1050 cm-1.

Source