Draw the structural formula of diisopentyl ketone. Draw the structural formula of 2,4-pentanedione. Draw the structure of the oxime of cyclopropanone. Which compound is the tertiary (3°) amide? None of the above. CH3 NH2 H3C CH2 CH3 The reaction of 1-pentanol with Jones reagent (CrO3/H2SO4) gives aldehyde, ketone, and carboxylic acid.
The correct answer and explanation is:
Correct Answers:
- Structural Formula of Diisopentyl Ketone:
Diisopentyl ketone has the structure:
(CH₃)₂CHCH₂COCH₂CH(CH₃)₂
It is a ketone with two isopentyl (3-methylbutyl) groups attached to the carbonyl carbon. - Structural Formula of 2,4-Pentanedione:
Also known as acetylacetone, the structure is:
CH₃COCH₂COCH₃
It has two ketone groups at carbon positions 2 and 4 in a 5-carbon chain. - Oxime of Cyclopropanone:
Replace the carbonyl oxygen (C=O) of cyclopropanone with =N–OH:
Structure:
Cyclopropyl–C=NOH (where the C=NOH replaces the original carbonyl of cyclopropanone) - Which compound is the tertiary (3°) amide?
Answer: None of the above.
A tertiary amide is defined as a compound with a carbonyl group (C=O) bonded to a nitrogen atom that is further bonded to two carbon groups (i.e., no hydrogen directly on nitrogen).
The given compounds — CH₃, NH₂, H₃C–CH₂–CH₃ — are not tertiary amides. - Reaction of 1-Pentanol with Jones Reagent (CrO₃/H₂SO₄):
The reaction gives a carboxylic acid, specifically pentanoic acid.
Jones reagent is a strong oxidizing agent, and when reacting with primary alcohols like 1-pentanol, it oxidizes them all the way to carboxylic acids, not stopping at aldehydes.
Explanation (300 words):
This question covers several key organic chemistry topics: ketone structure, diketones, oximes, functional groups, and oxidation reactions.
1. Diisopentyl Ketone:
This is a symmetrical ketone where both sides of the carbonyl are bonded to isopentyl groups (3-methylbutyl). Recognizing the branched nature of isopentyl is key.
2. 2,4-Pentanedione:
This molecule is a beta-diketone. It has a notable chemical behavior, often undergoing keto-enol tautomerism. This structure is common in chelation chemistry due to its ability to bind metal ions.
3. Oximes:
An oxime forms when a ketone or aldehyde reacts with hydroxylamine (NH₂OH). Cyclopropanone is a strained, highly reactive ketone. Its oxime has the formula cyclopropyl-C=NOH, and is less stable due to ring strain.
4. Tertiary Amides:
A tertiary amide must have no hydrogen atoms on the nitrogen. None of the provided fragments describe an amide structure, let alone a tertiary one.
5. Jones Oxidation:
Jones reagent is used to oxidize alcohols. Primary alcohols like 1-pentanol first form aldehydes but then proceed to carboxylic acids under the strong oxidative conditions. Only secondary alcohols are oxidized to ketones. Thus, the product here is pentanoic acid.
Understanding the nature of these functional groups and their reactions helps in mastering organic synthesis and compound identification.