JNTU B.Pharmacy I Year PHARMACEUTICAL ORGANIC CHEMISTRY - I Previous Question Paper (June - 2022 - R17)

The IUPAC system for naming open-chain alkanes follows these systematic rules:

1. Identify the longest continuous carbon chain, which serves as the parent alkane name.
2. Number the chain starting from the end that gives the lowest possible locant (number) to the first substituent encountered.
3. If multiple substituents are present, list them in alphabetical order. Use prefixes like di-, tri-, or tetra- for identical substituents, though these are ignored during alphabetization.
4. If two chains of equal length are present, select the one with the maximum number of substituents.
5. When numbering from both ends results in the same set of locants, assign the lower number to the substituent that appears first alphabetically.
6. Combine the locants and substituent names with the parent alkane name, using hyphens to separate numbers from words and commas to separate numbers from each other.

Tartaric acid (2,3-dihydroxybutanedioic acid) exhibits stereoisomerism due to two chiral centers. Its conformations include the (+)-tartaric acid, (-)-tartaric acid, and the internally compensated meso-tartaric acid.

A pair of enantiomers is represented by (+)-tartaric acid and (-)-tartaric acid, as they are non-superimposable mirror images of each other. A pair of diastereomers is represented by (+)-tartaric acid and meso-tartaric acid, as they are stereoisomers that are not mirror images of each other.