Abstract
(1) In aqueous solution acetoin and carbon dioxide are formed from pyruvic acid and acetaldehyde by the action of thiamine only when two equivalents of alkali are added to one molecule of thiamine.
(2) Thiaminedisulfide and the other tertiary thiazol derivatives can not catalyse this acyloin condensation under the same conditions.
(3) From these results and the other reports from our laboratory, we discussed the mechanism of thiamine action and presented a new reaction scheme for the acetoin formation and the decarboxylation of pyruvic acid.
