Question

Write the IUPAC name of the given compound:

Answer 1

The IUPAC nomenclature of organic chemistry is a method of naming organic chemical compounds that is recommended by the International Union of Pure and Applied Chemistry in chemical nomenclature (IUPAC). Any possible organic compound should, in theory, have a name that can be used to generate a clear structural formula.

Complete answer:
Rules to write IUPAC name of any organic compound –
Find the carbon chain with the longest length. This is referred to as the parent chain.
Make a list of all the substitutes (groups appending from the parent chain).
From the end of the parent chain, count the carbons until the substituents have the lowest number. When comparing two sets of numbers, the "lowest" sequence is the one that includes the lowest number at the time of the first difference. If two or more side chains are in the same place, the one that will appear first in the name should be assigned the lowest number.
If the same substituent appears multiple times, the position of each point where the substituent appears is given. A prefix also indicates the number of times the substituent group appears (di, tri, tetra, etc.).
If there are two or more separate substituents, they are identified alphabetically using the base name as the starting point (ignore the prefixes). When placing the substituents in alphabetical order, the only prefix used is iso, as in isopropyl or isobutyl. Even as compared to each other, the prefixes sec- and tert- are not used in deciding alphabetical order.
If chains of equal length compete for the parent chain's range, the decision is made in the following order:
a) The chain that has the most side chains.
b) The chain with the smallest number of substituents.
c) In the smaller side chain, the chain with the most carbon atoms wins.
d) The chain with the fewest branching on its side chains.
The prefix cyclo- occurs immediately in front of the base name to denote a cyclic (ring) hydrocarbon.
Now, according to the rules, the IUPAC name for the compound given below –

$1 - hydroxy - hex - 5 - ene - 2 - one$ .

Note:
The name of the compound is written in alphabetical order, starting with the substituents and ending with the base name (derived from the number of carbons in the parent chain). Between numbers, commas are used, and between letters and numbers, dashes are used. The name has no spaces in it.