Identify the reagents necessary to achieve each of the transformations below. I
ID: 1050650 • Letter: I
Question
Identify the reagents necessary to achieve each of the transformations below.
I understand you need Na, NH3 to make a trans alkene, but I do not understand why En would be reaction. You do not have to answer all of them but an explanation would be great. Thank you!
Incorrect + En Br Choose from reagents (A-H) 1) NaNH2 4) Mel 2) Mel 5) Na, NH3 () 3) NaNH2 6) Os04, NMO 1) Na, NH3 () 2) Br 1) Na, NH3 () 1) H2, Lindlar's catalyst 2) Os04, NMO2) Br2 2 1) H2, Lindlar's catalyst 2) MCPBA 1) H2, Lindlar's catalyst 1) Na, NH3 () 2) OsO4, NMO 2) MCPB/A 3) H3O 1) NaNH2 4) Mel 2) Mel 5) H2, Lindlar's catalyst 3) NaNH2 6) Os04, NMO If a reaction can be achieved by multiple reagents above, place answers in ascending order separated by a comma (e.g. A,C). Reagent(s):Explanation / Answer
Answers:
1. D......................Triple bonds reduced to double bonds under lindlar hydrogenation conditions. The olefin obtained is brominated which gives syn bromo derivative. En stands for enantiomer and another enantiomer can also form in the reaction.
2. F..................... OsO4 oxidation of double bonds give syn diols.
3. G......................Reduction of triple bonds under Na/liq. NH3 conditions yields trans alkenes. Oxidation of a transalkene gives an epoxide whose treatment with aqueous acid results in anti diols.
4. H................Successive alkylation of acetylene, followed by hydrogenation under lindlar conditions and then oxidation of the olefin gives the target syn diol.
5. A........... Successive alkylation of acetylene, followed by hydrogenation under Na/liq. NH3 gives trans alkene which upon oxidation with OsO4 gives anti diols