1. Reaction Acidity Synthesis
Alkynes
Reaction
Acidity
Synthesis

2. s-Complex of Acetylene
p-Bonds

3. Hydrocarbon Comparison

4. Alkyne Nomenclature

5. Enes with Ynes

6. Endiyne Antitumor Agents

12. Catalytic Hydrogenation

13. Lindlar’s Catalyst

14. H2 on a Poisoned Catalyst Prevents Over-Reduction cis Alkenes

15. Dissolved Lithium in NH3 trans Alkenes

16. Addition of HX

17. Br2 Addition

18. Oxymercuration Hydration Markovnikov

19. Enol – Keto Tautomerization Intermolecular

20. Oxymercuration Mechanism

21. Hydroboration Hydration Anti-Markovnikov

22. Hydroboration Mechanism

23. Draw the Products

25. Ozonolysis

26. Acidity of Terminal Alkynes

27. Acetylide Formation

28. Alkylation of Acetylide Ions Homologations using SN2 rxn

29. Multi-step Syntheses

30. Retrosynthetic Analysis Begin with the Product

31. Fill in the Reagents

32. How Many Steps?

33. 5 Steps

34. An unknown compound (A) has a formula of C11H14
An unknown compound (A) has a formula of C11H14. Treatment of A with H2/Pd-carbon gives B (C11H20). Treatment of A with H2 on a Lindlar catalyst gives C (C11H16). Ozonolysis of C followed by workup with Zn, HOAc affords formaldehyde and the tricarbonyl compound shown below.

35. Schematic of the Problem

36. An initial approach to this problem is to determine the number of degrees of unsaturation in each of the molecules A, B, and C.
When A (C11H14, 5o unsat.) is hydrogrenated, B (C11H20, 2o unsat.) is formed. That means that 3 p bonds reacted (3 mol. equivalents) to form B.
When A is treated with H2 over a Lindlar (poisoned) catalyst, 1 mol equiv. of H2 reacts. Since this reaction is specific for the reduction of alkynes to alkenes, 2 of the 3 p bonds in A are in the form of a triple bond. The remaining p bond must be an alkene.
We have accounted for three of the five degrees of unsaturation in A, therefore the other two must be rings since they do not react with H2.

37. Propose Structures for A, B, and C