Propyl group
In organic chemistry, a propyl group is a three-carbon alkyl substituent with chemical formula for the linear form. This substituent form is obtained by removing one hydrogen atom attached to the terminal carbon of propane. A propyl substituent is often represented in organic chemistry with the symbol Pr.
An isomeric form of propyl is obtained by moving the point of attachment from a terminal carbon atom to the central carbon atom, named isopropyl or 1-methylethyl. To maintain four substituents on each carbon atom, one hydrogen atom has to be moved from the middle carbon atom to the carbon atom which served as attachment point in the n-propyl variant, written as.
Linear propyl is sometimes termed normal and hence written with a prefix n-, as the absence of the prefix n- does not indicate which attachment point is chosen, i.e. absence of prefix does not automatically exclude the possibility of it being the branched version.
In addition, there is a third, cyclic, form called cyclopropyl, or c-propyl. It is not isomeric with the other two forms, having a different chemical formula, not just a different connectivity of the atoms.
Examples
is an ester which has the n-propyl group attached to the oxygen atom of the acetate group.Image:Propyl acetate.svg|thumb|center|Chemical structure of propyl acetate.