天然ビタミン油よりビタミンA濃縮物を経済的に製造する方法の研究-VII

ビタミンA濃縮物のエステル化(其の2)ケテンによるアセチル化

抄録

Acetylation of vitamin A concentrate was examined, using ketene (CH=C=O) prepared in the generator illustrated in fig. 1. In the generator, vapour of refluxing acetone came in contact with a glowing grid of resistance wire and underwent cracking to produce ketene, CH₄, CO etc., and the ketene evolved in the gas stream along with CH₄ and CO was bubbled through the benzene solution of vitamin A concentrate.
The following results were obtained.
1). At room temperature, ketene reacted readily with vitamin A concentrate to give its acetate, and no catalyst was needed for this reaction.
2). The amount of ketene to complete acetylation was one mole per one OH group of vitamin A concentrate to be acetylated.
3). The loss of vitamin A due to destruction scarcely occurred in this method.
4). This method of acetylation was far simpler and more economical in the technique and operation than that with acetyl chloride and pyridine.