The ancient Egyptians had less care for the chirality of hands Pharaohs,with two left hands or two right hands-they just didn't seem to notice
Fischer Mirror Images Easy to draw,easy to find enantiomers,easy to find internal mirror planes. Examples: CH3 C CH3 -CI CI- H H C -H H一 -C H CH3 CH3 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: (S) CH3 H-CI CI-H (S) H3
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. HH CH3 c- C=C H3C H cis-2-butene trans-2-butene