Which of the following is/are incorrect IUPAC name? (A) 3-Ethyl butane (B) 1 -Methyl heptane (C)

Which of the following is/are incorrect IUPAC name? (A)...

Key Concepts

Substituent Naming and Multiplicity

When naming compounds, each substituent attached to the parent chain must be identified using standard names. When multiple identical substituents are present, prefixes such as di-, tri-, etc., are used to denote their number. Each substituent is also assigned a locant number to indicate its position on the parent chain, and these locants are listed in a manner consistent with the lowest set of locants rule.

Lowest Set of Locants Rule

The lowest set of locants rule requires that the numbering of the carbon atoms in the parent chain is done in a way that gives the substituents the lowest possible numbers. This rule prevents ambiguity and ensures consistency in naming by minimizing the numerical positions associated with substituents, thereby achieving the simplest numerical labeling.

IUPAC Nomenclature

IUPAC nomenclature is the systematic method established by the International Union of Pure and Applied Chemistry used to name organic chemical compounds. It ensures that each compound has a unique and unambiguous name by applying a set of standardized rules that consider the structure, substituents, and functional groups present in the molecule.

Longest Chain Rule

The longest chain rule involves identifying the longest continuous chain of carbon atoms in a molecule, which forms the base of the compound’s name. This chain must be selected so that it also includes the maximum number of substituents possible, as it is fundamental in determining the parent name and subsequent numbering of the substituents.

Transcript

00:02 All right.

00:03 In this problem, we are given some of the iupac names of the organic compound.

00:07 We have to identify the names which are incorrect iupac names.

00:11 So let's start with the first one.

00:13 The first name is three ethyl butane.

00:16 As per the name, if we write the structure, it can have the structure, ch3, ch2, ch2, ch bonded to ch3.

00:24 And this carbon is also bonded to ethyl room, that is ch2, ph3.

00:29 Now if we provide number to the carbon, in the longest chain we can see this carbon this compound consists of five carbon atoms with one of a carbon atoms substituted by methyl group so this will get carbon one two three four and carbon five carbon three is substituted by a methyl group so the correct iopac name for this compound would be three methyl pentane instead of three thyl butane so this name is incorrect iupacian name.

01:07 Moving on to the second name, we have one methyl haptane.

01:11 As for this name, this compound has a chain of seven carbon atoms with first carbon substituted by a methyl group.

01:18 So we can write the structure of this compound as ch2 bonded to methyl group.

01:25 Then ch2, ch2, ch2, ch2, ch2, h2 and c h3.

01:34 Now if we look at this compound, this compound has only one possible chain where all the carbon atoms are in the straight chain.

01:43 That is, this is carbon 1, 2, 3, 4, 5, 6, 7th and 8...

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