Depto. Química Orgánica


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Where I am Problems and exercises Molecular panel Home
Look for the longest chain bearing the triple bond.

The chain is numbered assigning to the triple bond the lowest possible numerals, exception made when there is a dominant function.

If there are substituents they must be preceded by the corresponding numerals.
In the case there are two possible equivalent numberings, that with the lowest substituent numerals will be taken.

Chains bearing a triple bond that must act as a substituent are named "alkynyl"
When one finds an open chain with triple and double C=C bonds (alkenynes), the numbering will start by the nearest end to one of them.

If the double C=C and triple bonds are equidistant to both ends of the chain, the double bond takes the priority.

Should there be other substituents of higher priority, the numbering will start by them.

Here you are some key examples: