WHAT ARE ALKYL GRUPS PLEASE EXPLAIN WITH STRUCTURES

Alkyl Groups and the Symbol R
Alkyl groups are the groups that we identify for purposes of naming compounds. They are
groups that would be obtained by removing a hydrogen atom from an alkane:

 

 

 

 

 

While only one alkyl group can be derived from methane or ethane (the methyl and ethyl
groups, respectively), two groups can be derived from propane. Removal of a hydrogen from
one of the end carbon atoms gives a group that is called the propyl group; removal of a
hydrogen from the middle carbon atom gives a group that is called the isopropyl group.
The names and structures of these groups are used so frequently in organic chemistry that
you should learn them now. See Section 4.3C for names and structures of branched alkyl
groups derived from butane and other hydrocarbons.
We can simplify much of our future discussion if, at this point, we introduce a symbol
that is widely used in designating general structures of organic molecules: the symbol R.
R is used as a general symbol to represent any alkyl group. For example, R might be a
methyl group, an ethyl group, a propyl group, or an isopropyl group: