Question

Question: Write the IUPAC name of the following:

Answer 1

There are some rules on the basis of which names are given to the organic compounds. These names are decided on the basis of IUPAC system. In this system, the prefix of the compound name indicates the number of carbon atoms and the suffix of the compound indicates the number of bonds between the carbon atoms.

Complete step by step answer:
In this question we have to find the $IUPAC$ name of the following compound.

In this compound there are five carbon atoms in the ring and there is one double bond in this compound and one alcohol functional group is present. Since there are five carbon atoms in the ring, prefix pent will be used. Since it is a cyclic compound, word cyclo will be used before pent. So now the prefix is cyclopent. According to the rules of nomenclature, suffix ene is used to represent double bond. One alcohol group is also present to represent this alcohol group e of ene will be replaced with ol. Also we have to specify the position of this alcohol group. According to nomenclature rules if double bond and functional group both are present then the preference will be given to the functional group. So numbering will start from the alcohol group and it will get first position, so now suffix is $3 - ene - 1 - ol$. Position of the double bond is $3$ because in this compound there will be no effect whether we start numbering from left or right, the bond will get the same position from both the ways(either clockwise or anticlockwise). Now, combining both prefix and suffix that is cyclopent $3 - ene - 1 - ol$ is the IUPAC name of this compound.

Note:
In this case, the bond was getting the same position from both sides but if we were given the compound, whose bond would be at different position from different sides, we would start numbering from the side from which bond (from that side) will get the lowest number.