Question

The IUPAC name of

• A. 3-(Formylmethyl)hexane-1, 6-dial
• B. 2-(Formylmethyl)butane-1, 4-dicarbaldehyde
• C. 2-(Formylmethyl)butane-1, 4-tricarbaldehyde
• D. None of the above

Answer 1

The correct option is A

3-(Formylmethyl)hexane-1, 6-dial

Irrespective of how we choose the longest chain, we will have to exclude one $-\stackrel{O}{\stackrel{||}{C}}-H$ group.

Note that the compound given differs from

If this compound had been given, its name would have been as Butan-1,2,4-tricarbaldehyde

$C{H}_{3}CHO$ is ethanol

HCHO is methanal

is Butanal

In the above tree cases, $-\stackrel{O}{\stackrel{||}{C}}-H$ is part of the parent chain

But

is Benzene carbaldehyde (also known as Benzaldehyde)

In our question ,

is given

Here we include as many -CHO groups as possible in the longest chain.Thus it is numbered as above (to give lowest possible number to the substituents -$C{H}_2-CHO$) the substituent is called formylmethyl.

6 carbons = hex.

Since there are no carbon - carbon multiple bonds, primary suffix = ane; secondary suffix = dial.

Hence the IUPAC name is

(a) 3 -(Formylmethyl)-hexane-1,6-dial

Note the parentheses indicating substituted substituent.