UPSC Combined Geo-Scientist, Mains · 2024 · Mains Paper III
Q8(d). Ozonolysis, then intramolecular aldol condensation
Question
Identify the products X and Y in the following reaction sequence. Explain the mechanism of conversion of X to Y: [structure of the cycloalkene, atoms numbered 1–7, given in the paper], O₃/Me₂S → X; MeONa/MeOH → Y.
Model answer
The free solution for 2024 answers questions 1, 4, 5, 6, 7 and 9, the ones picked in its time plan. Question 8 is answered in full in the Geo-Scientist Chemistry Paper III, 2021 to 2025 book, with every part of every paper.
Part of VKC Basic
Read the key points and the full model answer with VKC Basic
VKC Basic (₹999 for 6 months) opens every solved answer, the notes, the handbook and the daily answer archive. Every Mains test series includes it.
Printed copy and Kindle
UPSC Combined Geo-Scientist (Main) Chemistry Paper III: Model Answers 2021 to 2025
- All ten questions of each paper, with the question printed above its answer
- Instruments drawn as labelled diagrams, numericals worked with units
- Topic-wise weightage and a topic-wise index
Coversozonolysisintramolecular aldol condensationE1cBketo-aldehyde1-acetylcyclohexene
All parts of Question 8
- 8(a)(i) 2-Acetylbenzaldehyde with KCN: internal hydride shift to a lactone5 marks
- 8(a)(ii) Hydroboration–oxidation of norbornene: exo-norborneol5 marks
- 8(b) Photolysis of two ketones: Norrish Type II and Type I5 marks
- 8(c) Hexane-2,5-dione with acid: Paal–Knorr furan synthesis5 marks
- 8(d) Ozonolysis, then intramolecular aldol condensation10 marks