Question

Propose a reasonable synthetic route for each of the following multistep syntheses. Show all isolable intermediates.

D. E.

Answer 1

NaNH2 excess H2. Pt Br2, CCl4 CH3l Explanati on: Addition of Br2 to alkene produces a dibromo compound as product. NaNH2 is a strong which gives eliminati on reaction and produces acetylide anion which on further reaction with methyl iodi de produces an extended carbon chain as product. Now, reduction of triple bond with H2. Pt produces alkane as product. NaNH2 excess CH3CH2I NaBH4 Explanati on: NaNH2 is a strong base which abstracts acidic proton and produces acetylide ion as product. Now, reaction of acetylide iorn with ethyl iodi de produces an extended carbon chain as product. Now, hydroboration - oxi dation of alkyne with Hg(OAc)2, H2O, NaBH,4 produces ketone as product.