Question

The IUPAC name of acraldehyde is
A.Prop-1-ene-2-al
B.Prop-2-ene-3-al
C.Prop-2-ene-1-al
D.Prop-ene-1-al

Answer 1

To answer this question, you must recall the rules for IUPAC nomenclature of a compound. Acraldehyde is an aldehyde and the suffix will be –al. While numbering, the functional group with the highest priority should get the smallest number.

Complete step by step answer:
We must follow the rules for the IUPAC nomenclature. These rules make sure that each compound has a different unique name.
First of all, we mark the longest chain, then identify the group attached to the chain. The next step involves the numbering of the group in such a way that the carbon to which the substituent group is present has the lowest number. Then we must determine the functional group with the highest property to be used as a suffix and other components are arranged alphabetically in the name of the compound.
The functional group attached to the main chain is the aldehyde group and thus we start the numbering of the chain from the carbonyl carbon. There are a total of three carbon atoms in the compound so the word root for the carbon chain will be prop-.
At the second carbon, we have a double bond as well which will be the suffix (-ene) after the word root.
The secondary suffix will be of the functional group aldehyde (-al).
Thus, the IUPAC name of the compound can be written as prop-2-en-1-al.

Thus, the correct answer is C.

Note:
The order of preference for choice of the principal functional group for nomenclature is:
$- COOH > - S{O_3}H > - {(CO)_2}O > - COOR > - COX > - CON{H_2} > - CN$
$> - CHO > C = O > - OH > - SH > - N{H_2} > - OR > C = C > - C \equiv C -$
It should be taken into note that the secondary suffix should be added to the primary suffix by dropping its terminal ‘e ‘.
In the question, the primary suffix has as -ene (for alkene) and the secondary suffix is -al (for aldehyde). Hence, the suffixes are written together as -en-al.