Flashcard: Mastering Chirality and Stereochemistry — 18 carte

Stereochemistry — definition?

Study of molecules with same atoms, different 3D arrangements.

Chirality — property?

Non-superimposable on mirror image, usually with a stereocenter.

Achiral molecules — example?

Superimposable mirror images, symmetrical structures.

Enantiomers — difference?

Mirror-image stereoisomers, rotate plane-polarized light oppositely.

Diastereomers — difference?

Non-mirror stereoisomers, differ at some but not all chiral centers.

Chiral center — identification?

Carbon bonded to four different groups.

R/S configuration — process?

Prioritize substituents, trace sequence, assign R or S.

Optical activity — effect?

Rotates plane-polarized light; enantiomers rotate oppositely.

Enantiomers — physical properties?

Identical except for optical rotation and chiral interactions.

Epimers — difference?

Differ at only one chiral carbon, excluding anomeric carbon.

Anomers — formation?

Formed during sugar cyclization, differ at anomeric carbon.

α-anomer — hydroxyl position?

Trans to CH₂OH group in cyclic sugar.

β-anomer — hydroxyl position?

Cis to CH₂OH group in cyclic sugar.

Biological chirality — significance?

Enzymes recognize specific enantiomers, affecting activity.

Drug enantiomers — effect?

One active, other inactive or harmful; stereospecificity critical.

Chirality in flavors — example?

(R)-limonene smells like orange; (S)-limonene like lemon.

Determining R/S — key step?

Prioritize groups, trace sequence, flip if lowest in front.

Chirality — importance?

Affects biological activity, drug efficacy, and sensory properties.