1533
A proposed mechanism for the reaction indicates that the ethyl side of the ester is eliminated as ethylene through a concerted six - membered cyclic transition state , and the unstable intermediate glycidic acid decarboxylates rapidly to give the corresponding aldehyde .
 Chemical: ethyl; Chemical: ethylene; Chemical: glycidic acid; Chemical: aldehyde
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: ethyl; Chemical: ethylene; Chemical: glycidic acid; Chemical: aldehyde