Question

5. What is the IUPAC name for compound shown below? CH3

Answer 1

Step 1

Identify the longest carbon chain and functional group present in the compound. Number the chain in such a way so that functional group gets the lowest number. Then substituent number is given lowest numbering.

If more than one type of same functional group is present di, tri, tetra as prefix is added to the suffix of functional group.

If more than one type of different functional groups are present, one is considered as principle functional group and other as substituent.

Step 2

Name that longest carbon chain by the root name on the basis of number of carbon atoms.

For 1 carbon - meth

For 2 carbons - eth

For 3 carbons - prop

For 4 carbons - but

For 5 carbons - pent

And so on

For cyclicalkanes, 'cyclo' is added as prefix.

Step 3: Suffix should be added to this root name according to the functional group identified along with the number of the carbon on which functional group is present.

Step 4: Name and number the substituent present on the chain.

Substituents can be any alkyl group, halogen group, nitro, alkoxy etc.l

This will be present as prefix in the name. If more than one group of the dame substituent will be there, a prefix will be added to substituent name such as di, tri ,tetra etc.

If more than 1 different substituent is there, then alphabetical order is followed for giving the lowest number.

And naming with be also done according to alphabetical order.

Let's name it now

4 3 functional = ketone Laffix ene Root name ycaubn but >ito a alkane au mo donble bond.+ cyci'c in nahre -2lo position fanctibnal pro dubatithnmelhy pesition Se the name wil be &Metylaylokutangng Pasihon kelone yclic hruchure ubetihuent Carbens ubitituent