21775
Gas chromatography - olfactometry ( GC - O ) and multidimensional gas chromatography - mass spectrometry ( MDGC - MS ) of the fraction which contained a significant amount of the target unknown compound revealed the cyclic 1 , 4 - diketone , cis - 2 , 6 - dimethyl - 1 , 4 - cyclohexanedione , which had a pungent odour , and was thus first identified in roasted coffee .
 Chemical: cis - 2 , 6 - dimethyl - 1 , 4 - cyclohexanedione
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: cis - 2 , 6 - dimethyl - 1 , 4 - cyclohexanedione