Q9(a). Gramine route to indole-3-acetic acid; photolysis of cyclodecanone
Predict the products C and D in the given reaction schemes (i and ii). Provide suitable mechanisms for both the schemes. [(i) indole + HCHO + (CH₃)₂NH → A; Me₂SO₄ → B; NaCN, then H₃O⁺ → C. (ii) cyclodecanone, hν → D. Schemes given in the paper]
Model answer
The free solution for 2022 answers questions 1, 4, 5, 6, 7 and 10, the ones picked in its time plan. Question 9 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.
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
CoversgramineMannich reactionindole-3-acetic acidNorrish type IIcyclodecanone photolysistransannular hydrogen abstraction
All parts of Question 9
- 9(a) Gramine route to indole-3-acetic acid; photolysis of cyclodecanone10 marks
- 9(b) Cannizzaro reaction: effect of para substituents on the rate5 marks
- 9(c) IR: C=C stretch of small-ring alkenes; class of a nitrogen compound5 marks
- 9(d) Four conversions: structures of the products10 marks