Consider the following reaction. + PhLi (2 eq.) then water a) Propose a structure for the final product. b) Give a complete mechanism for the transformation. c) Draw an energy diagram of the transformation and briefly comment on the relative energies of the starting material, final product, and any intermediate(s), and about the rate determining step.

2. Using the curved-arrow formalism, provide a mechanism that accounts for the following transformation. H2SO4 ÓH

2. Show how the compounds below can be made in two ways in a single step from the appropriate starting materials and reagents. a) b) a cuprate an alkene H an alkyne an alkyne

Show how to prepare each alkyne from the given starting material. In part (c), D indicates deuterium. Deuterium-containing reagents such as BD3, D2O, and CH3COOD are available commercially.

(a) Draw the products formed when propane is heated with Br2.  (b) Label major and minor products and explain with an energy diagram.

(ii) Draw the product R, including a detailed reaction mechanism for the conjugate addition reaction between the 1,3-dicarbonyl P and the a,ß-unsaturated ketone Q. Eto P OEt + Q OEt Et3N R (iv) Explain why conjugate addition is favoured over direct addition to Q in this case.

2) a. In the synthesis of Camptothecin, a potent antitumor and antileukemic agent isolated from the stem wood of a Chinese Nyssaceae tree, the following conversion is made. Come up with a reasonable mechanism for the following conversion using proper electron pushing and reasonable chemistry. CHO NH₂ of me N-CO,Et -CO₂Et NaOH, aq EtOH R₂NH b. The following reaction is an example of Mannich reaction. Please write a reasonable mechanism. HiH N-CO,Et -CO,H H R₂N H

A4.

Use line structures and write reaction equations for the following synthetic conversion. Show each reaction step by a complete reaction equation in which substrate, reagents and all possible organic products are given. Indicate major and minor products where applicable, but not in the final step. Show only the major product in the final step. No mechanisms and stereochemistry are required. Br

6) Give the products of each of the following reactions. a) b) d) H Li, NH3 CH3CH₂OH xo Na₂Cr₂O7 H₂O, H₂SO4, A H₂O LI, NH3 CH₂CH₂OH