3. On treatment with HBr, threo-3-bromo-2-butanol is converted into racemic 2,3dibromobutane, and erythro-3-bromo-2-butanol is converted into meso-2,3dibromobutane (a) Draw the cross formula structures of (i) 2,3-dibromobutane (ii) meso-2,3dibromobutane 1 (b) What type of stereoisomers are threo-3-bromo-2-butanol and erythro-3-bromo2-butanol? Give reason for your answer. (c) What appears to be the stereochemistry of the above reaction? Explain. Does it proceed with inversion or retention of configuration? Explain (d) With chemical equations and structures, show and explain how you would separate the 2,3-dibromobutane products using (+) tartaric acid