18559
The difluoromethyl ketones were assembled in three synthetic steps using a trifluoroacetate - release aldol reaction .
 Chemical: difluoromethyl ketones; Chemical: trifluoroacetate
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: difluoromethyl ketones; Chemical: trifluoroacetate