Question

7. (2 points) A graduate student attempted to make 1-methyl-1-cyclopentene by the elimination of HBr from 1-bromo-1-methylcyclopentane. The reaction was done by heating 1-bromo-1-methylcyclopentane in methanol. The student received a low yield of the desired 1-methyl-1-cyclopentene. Why do you think the yield was low? What could be done to improve the yield? CH3OH B .

A graduate student attempted to make 1-methyl-1-cyclopentene by the elimination of HBr from 1-bromo-1-methylcyclopentane. The reaction was done by heating 1-bromo-1-methylcyclopentane in methanol. The student received a low yield of the desired 1-methyl-1-cyclopentene. Why do you think the yield was low? What could be done to improve the yield?

Answer 1

#7) The reaction was done by heating - become - I-methylcyclopentase is methand, not only yield elimination product but also yield substitution product. Substitution Reaction : 3 halide HO 2M OCH Сн, ОН осна | 1 Choi 1 1-bromo-l-methybyclopentano i-methoxy-1- metripleykelopentare Elimination Reaction Teafiózy alkyl halide undergo E, scackos unimoleculoo elimination -Br

The Coabocation has two types of hydrogen at to undergo dimination different allone product. different pela - pasit wild luo Methylerocyclopentane Y t-methyl-1-cyclopentene Overall completo reaction CH₃OH 1- Broma-1-methyl Methylene Amethel- e - Cyclopentano oplagertare tedopentene ) Reaction of 1- Bromo-1-mothykoyplopentane exith methanol: CH₂OH

A - 1- baomo- I-methylcyclopentane 8-1- me thoxy-t-methylcyclopentane C. Methylene cyclopertane 3-l-methyl-i-cyclopentano Due to different product famed in single goaction, a desired 1-mother-tace yield was very low .. To improve the yield, the geachón uns Carried out sodium ethoxide in ethanal to Er is faster than E, in paesence of strong potheke 1-cyclopentan More Bubstituted albene + OCH₂ CH₂ Complete Reaction : - (Dokptoobumination) CH3CH, ONA, O or CH₂CH2OH 1. methyl-traplopertene 1 bomo imethel cyplopentand

like base In the passence of weak base like CH3CH, Ę zaction is fawred In the presence of strong base. (OH, RO , RN), & reaction is favored & unimalcula elimination soaction, in the gate determining stop , only one molcul concentration involves .. - Bimolecular elimination, both geactant and base concentration involve is the gate determining stop. Dehepleobrominataan :- The geaction was done by boating 1 bacomo - 1-methylcyclopentane with sodium ethocide in ethanol to yeed - methel. 1-cyclopentene Eto Na ELOH