Organic Chemistry

Organic Chemistry - Ch 11 555 Daley & Daleyc)d)COOHHCH 3COOHCH 3 OHCOOHHH OH H 3 C COOH H OH H 3 C OHCH 3 CH 2 CH 3 CH 2 CH 3CH 3CH 3CH 2 CH 3 CH 3 2 CH CH 3Cl H Cl H H Cl H ClCH 3CH 3HOCH 3CH 2 CH 3CH 2 CH 3CH 3CH 2 CH 3HOCH 3HCH 3OCH 2 CH 3HOCH 3CH 3Sample Solutiona) The first and second structures are enantiomers, the first and thirdare identical, and the first and fourth are enantiomers.11.6 Molecules with Two StereocentersDiastereomers arestereoisomers that arenot mirror images ofeach other.The atoms in stereoisomers bond in the same sequence buthave different spatial arrangements. Enantiomers are stereoisomersthat are mirror images of each other. All stereoisomers that are notenantiomers are diastereomers. When a molecule contains morethan one stereocenter, its stereoisomers exist in pairs that exhibit anenantiomeric relationship; that is, they are mirror images of eachother. They also exist in pairs that exhibit a diastereomericrelationship. That is, they are not mirror images of each other.Consider the following two structures of 3-chloro-2-butanol.HCH 3OHHCH 3OHHClClHCH 3CH 3To follow this discussion, make molecular models of the two structuresshown above. In these structures, both C2 and C3 are stereocenters.The atoms making up these two molecules have the same bondingorder yet are different in their spatial arrangement, therefore they arewww.ochem4free.com 5 July 2005