Enantiomers of 2-bromobutane

Exercise 8-8 Explain how, in the presence of bromide ion, either enantiomer of 2-bromobutane racemizes (Section 5-1B) in 2-propanone solution at a rate that is first order in Breand first order in 2-bromobutane. 

Make a model of one of the enantiomers of 2-bromobutane. Make a model of the enantiomer that results from an SN2 reaction in which the bromine is replaced by an OH. Make sure you have inversion of configuration. Look at the original enantiomer and visualize the OH coming in from the rear and displacing the bromine. 

First, let s look at how you can determine the configuration of a compound drawn as a perspective formula. As an example, we will determine which of the enantiomers of 2-bromobutane has the R configuration and which has the S configuration. 

Scheme 7.4. A representation of the process by which one of the enantiomers of 2-bromobutane provides racemic 2-pHi]butane.

Build a model of each of the enantiomers of 2-bromobutane (see pagb-... 

Figure 5-5 Measuring the optical rotation of the (-) enantiomer of 2-bromobutane with a poiarimeter.

For example, consider the radical chlorination of the S enantiomer of 2-bromobutane. In this case, the chlorine atom has several options for attack the two terminal methyl groups, the single hydrogen at C2, and the two hydrogens on C3. Let us examine each of these reaction paths. 

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