Give the IUPAC systematic name of acetoin.
Identify the reagents and conditions needed to convert acetoin into diacetyl.
An infra-red spectrum of acetoin is shown.
Explain the main features of this spectrum, referring to the peaks with wavenumbers above $1500\,\text{cm}^{-1}$.
State and explain how the infra-red spectrum of diacetyl would be different from the infra-red spectrum of acetoin.
If a sample of acetoin is reacted with concentrated sulfuric acid, one product is formed that does not show stereoisomerism. However, if a sample of acetoin is reacted with HBr, a mixture of a pair of stereoisomers is produced.
Give the structural formula of the product formed when acetoin reacts with concentrated sulfuric acid.
Explain why the product in (i) does not show stereoisomerism.
Explain why the product of the reaction of acetoin with HBr does show stereoisomerism.
Draw the two stereoisomers from (iii) using the conventional representation.