Question

Question 1(Soalan 1) An alkyne A, 4-methyl-2-pentyne can be prepared via dehydrohalogenation of compound B in the presence of KOH. Hydroboration of alkyne A produces a mixture of ketones, Dand E Alkuna A, 4-me til-2-pentuna boleh disediakan melalui tindak balas pendehidrohalogenan sebatian B dalam kehadiran KOH. Penghidroboratan alkuna A menghasilkan campuran keton, D dan E a) Draw the structures of B, D and E. Lukis struktur bagi B, D dan E. b) Give the reagent/condition for the hydroboration reaction. Berikan reagen/keadaan untuk tindak balas penghidroboratan c) Propose another method to produce alkyne A from an alkyl halide. Cadangkan kaedah lain untuk menghasilikan alkuna A daripada alkil halida. d) Draw the structures of the products obtained when alkyne A react with hot acidified KMnO4. Lukis struktur hasil yang diperolehi apabila alkuna A bertindak balas dengan KMnO4 berasid panas. [10 marks] Question 2 (Soalan 2) a) For the following reaction, state the type of reaction involved and draw the mechanism. Untuk tindak balas di bawah, nyatakan jenis tindak balas dan lukis mekanisme yang terlibat OH NC HCN [3 marks]

Answer 1

KOH heat Br

BHz H2PzNaOH + andtin mettiod tor atape tormahon NANHZ > heat Rom wih Koy KMn De + DH

Ouxton 2 O :0% CH CN CEN firxt Secord Star 8 Proton alsrachon to fong desired Procuok stap CN atteck