Fischer Mirror Images Easy to draw,easy to find enantiomers,easy to find internal mirror planes. Examples: CH3 CH3 C H CI H H C- H H H CH3 CH
Fischer Mirror Images Easy to draw, easy to find enantiomers, easy to find internal mirror planes. Examples: CH 3 H Cl Cl H CH 3 CH3 Cl H H Cl CH3 CH3 H Cl H Cl CH3
Fischer(R)and (S) 后用 Lowest priority (usually H) comes forward,so assignment rules are backwards！ Clockwise 1-2-3 is (S)and counterclockwise 1-2-3 is (R). Example: (S) CH3 H -CI C 一H (S) CH;
Fischer (R) and (S) Lowest priority (usually H) comes forward, so assignment rules are backwards! Clockwise 1-2-3 is (S) and counterclockwise 1-2-3 is (R). Example: CH 3 H Cl Cl H CH 3 ( S) (S)
Diastereomers Stereoisomers that are not mirror images. Geometric isomers(cis-trans). Molecules with 2 or more chiral carbons
Diastereomers Stereoisomers that are not mirror images. Geometric isomers (cis-trans). Molecules with 2 or more chiral carbons
Alkenes Cis-trans isomers are not mirror images, so these are diastereomers. H H CH3 C=C CH3 cis-2-butene trans-2-butene no C=C H fumaric acid,mp 287 C maleic acid,mp 138 essential metabolite toxic irritant
Alkenes Cis-trans isomers are not mirror images, so these are diastereomers. C C H H H3C CH3 cis-2-butene trans-2-butene C C H H3C CH3 H H O C O C H C H C O O H fumaric acid, mp 287 C essential metabolite o H C C C H C O O H O H O maleic acid, mp 138 C toxic irritant o
Ring Compounds Cis-trans isomers possible. May also have enantiomers. Example:trans-1,2-dimethylcyclopentane H CH, CH H CH CH enantiomers of trans-1,2-dimethylcyclopentane cis-1,2-dimethylcyclopentane(achiral) diastereomers Copyright2005 Pearson Prentice Hall,Inc
Ring Compounds Cis-trans isomers possible. May also have enantiomers. Example: trans-1,2-dimethylcyclopentane