Alkenes: ozonolysis and polymerization
- For the given reaction:[scheme: ring-C(H)=CH-ring KMnO_4/H^+ 'P' (major product), see figure]'P' is Answer: 3. [structure: ring-COOH] Key idea: hot or acidic KMnO₄ cleaves a C=C bond and oxidises each fragment fully to the carboxylic acid.... 1
- Which amongst the following molecules on polymerization produces neoprene? Answer: 3. H₂C=C(Cl)-CH=CH₂ Key idea: Neoprene is a polymer of chloroprene, 2-chlorobuta-1,3-diene. Chloroprene is CH₂=C(Cl)-CH=CH₂ , which... 1
- Compound X on reaction with O_3 followed by Zn/H_2O gives formaldehyde and 2-methyl propanal as products. The compound X is : Answer: 2. 3-Methylbut-1-ene Key idea: ozonolysis cuts the C=C bond and puts a C=O on each carbon. Working backwards: HCHO and mathrm(CH₃)₂C... 1
- An alkene on ozonolysis gives methanal as one of the product. Its structure is : Answer: 3. Cyclohexyl-CH ₂ -CH=CH ₂ Ozonolysis cleaves C=C and gives a carbonyl on each carbon. Methanal (HCHO) comes only from a terminal =... 1
- An alkene "A" on reaction with O_3 and Zn-H_2O gives propanone and ethanal in equimolar ratio. Addition of HCl to alkene "A" gives "B" as the major product. The structure of product "B" is : Answer: 3. H ₃ C-CH ₂ -C(CH ₃ )(Cl)-CH ₃ (see figure) Work back from the ozonolysis products. Propanone (CH₃)₂C=O and ethanal CH₃CHO join at... 1