IUPAC Parent Chain Help!
Hey all!
As per the current IUPAC Blue Book, I see that a parent chain must have the most amount of heteroatoms. However, that leads to confusion here:
OCCC(=O)O
The highest priority would be the carboxylic acid, so the chain would be CCCO? But this doesn't make sense, as I know the chain would be CCC.
I am struggling to understand the heteroatom priority. Below is the exact rule as per the Blue Book.
>In an acyclic compound consisting of individual atoms, alike or
different (an acyclic chain), the chain on which the nomenclature and
numbering is based is called the ‘principal chain’. When there is a
choice for the principal chain, the following criteria are applied, in
the order listed, until a decision is reached.
The principal chain:
(a) contains the greater number of heteroatoms of any kind;
(b) has the greater number of skeletal atoms;
(c) contains the greater number of the most senior acyclic heteroatom in
the following sequence: O > S > Se > Te > N > P > As
> Sb > Bi > Si > Ge > Sn > Pb > B > Al > Ga
> In >Tl.
Am I right in assuming all thats needed is to ensure that the hetero atom isn't terminal, i.e. is between 2 carbons?