5) Which method would work best in carrying out the following conversion? a) HBr
ID: 699125 • Letter: 5
Question
5) Which method would work best in carrying out the following conversion? a) HBr, then NaNH2 c) Br/H20, then NaNH2 b) Br2, then NaNH2 6) What is the major product of the reaction shown? 2 HCI a) 1,1-dichlorobutane b) 1,2-dichlorobutane c) 2,2-dichlorobutane d) 2,3-dichlorobutane 7) Which reagent below would be used to convert pent-2-yne into trans-pent-2-ene? 8) What is the relationship between the keto and enol forms of acetone (CH COCH:)? 9) How would you carry out the following conversion? a) NaNH: /NH b) H2 /Lindlar Pd c) Na/NH d) H O/HgSO4/HSO a) resonanc e structures b) diastereomers c) different conformations d) constitutional isomers CH, CH,CH C CH CHCH CH2CH,Br a) H2/ Lindlar Pd, then HBr c) HBr (1 equivalent), then H2/Pd b) H2/Lindlar Pd, then HBr (with peroxide) d) Br (1 equivalent) then H2/PdExplanation / Answer
5) option B is correct
Explanation: Addition of Br2 forms dibromo compound as product. NaNH2 gives dehydrohalogenation and prodcues alkyne as product.
6) option C is correct
Explanation: Addition of HCl to alkyne produces more substituted alkyl halide as product.
7) option C is correct
Explanation: Na, NH3 converts alkyne to trans-alkene.
8) option A is correct
9) optoin B is correct
Explanation: Reduction of alkyne with H2, Lindlard's catalyst produces alkene as product. Addition of HBr, peroxide to alkene produces the required alkyl halide as product.