What are the structures of molecules of biocetyl C4H6O2 a substance with the aroma of butter it contains no ring or carbon-carbon multiple bonds?

Answer 1

http://en.wikipedia.org/wiki/Diacetyl

You will find your answer there

Answer 2

Biocetyl C4H6O2 is likely a straight-chain ester molecule derived from butyric acid, with a ketone functional group. Its structure may resemble butyl acetate, with the formula CH3(CH2)2COOCH3. This configuration is consistent with its butter-like aroma, as esters are commonly associated with fruity or sweet smells.