Example (Continued) 3 CH3 1 CH:CH2CH-CH H4 CHCH2CHCH3 2 Counterclockwise (S) Chapter 5 16
Chapter 5 16 Example (Continued) CH3 CH3CH2CH=CH CH2CH2CH2CH3 H 1 2 3 4 Counterclockwise (S)
Solved Problem 1 Draw the enantiomers of 1,3-dibromobutane and label them as(R)and(S).(Making a model is particularly helpful for this type of problem.) CH2一CH2-CH-CH Br Br Solution The third carbon atom in 1,3-dibromobutane is asymmetric.The bromine atom receives first priority, the(-CH2CH2Br)group second priority,the methyl group third,and the hydrogen fourth.The following mirror images are drawn with the hydrogen atom back,ready to assign(R)or(S)as shown. CH,CH,Br CH,CH,Br CiH H Br Br (R) (S) Chapter 5 17
Chapter 5 17 Draw the enantiomers of 1,3-dibromobutane and label them as (R) and (S). (Making a model is particularly helpful for this type of problem.) The third carbon atom in 1,3-dibromobutane is asymmetric. The bromine atom receives first priority, the (–CH2CH2Br) group second priority, the methyl group third, and the hydrogen fourth. The following mirror images are drawn with the hydrogen atom back, ready to assign (R) or (S) as shown. Solved Problem 1 Solution