Isomerism

Chiral compounds have non-superimposable mirror images (enantiomers) and typically feature a carbon atom bonded to four different groups.Rules to Identify Chiral Compounds1.Chiral Center: Carbon atom bonded to four different groups.2.Non-Superimposable: Mirror images that cannot be superimposed.3.No Internal Plane of Symmetry(POS): No plane dividing the molecule into two identical halves.4.Optical Activity: Rotates plane-polarized light.The given structure does not have chiral center and for any confusion for the carbon at the top, since there is a plane of symmetry, the carbon is not a chiral center.Therefore, Compound I is not chiral.II has a chiral center and also does not have POSTherefore, Compound II is chiral.The carbonyl carbon is not a chiral center, as it is bonded to two identical groups (part of the ring).Therefore, Compound III is not chiral.The carbon bonded to , and the ring is a chiral center since it has four different groups attached.Therefore, Compound IV is chiral.

1.Conformational Isomers (Conformers):Conformational isomers are briefly separate variants of the same molecule that can be converted into one another by rotation around single bonds. They are usually interconvertible at room temperature and are not considered different compounds.2.Structural Isomers: Structural isomers are compounds that have the same molecular formula but different connectivity of their atoms. This means the atoms are linked together in different ways, resulting in different structures and potentially different chemical properties.3.Enantiomers: Enantiomers are pairs of molecules that are non-superimposable mirror images of each other. They have the same molecular formula and connectivity of atoms but differ in the spatialarangement of atoms. Enantiomers typically have identical physical properties except for their interaction with plane-polarized light and reactions in chiral environments.4.Positional Isomers: Positional isomers are a type of structural isomer where the basic carbon skeleton remains unchanged, but the position of a functional group, substituent, or multiple bonds differ. This variation can lead to different physical and chemical properties.

Pyranose: Structure has a six-membered ringFuranose: Structure has a five-membered ringThe hydroxyl group on the first carbon (anomeric carbon) is down, indicating an alpha configuration.$ $

✅Correct Answer: Option A