Question

Synthesis using Carbonyla-Substitution Chemistry Preamble This experiment involves the synthesis of target molecules using a-substitution chemistry. You are assigned two target molecules, one of which is best synthesized by an alkylation approach, while the other is best synthesized by an addition or condensation approach. My two target molecules are number 2 and number 12 in the last page. You must do the following: 1. Perform a retrosynthetic analysis on the two target molecules assigned to you. In each case the organic starting material (what you have to work backwards toward) depends upon the target. For targets 1-10, the starting material is either malonic ester or acetoacetic ester and any halide. For targets 11-16, the starting material is any four carbon halide. Draw a retrosynthetic scheme; use the rightwards double arrow to show functional group transformations and disconnections. 2. Propose the forward synthesis (based upon the retrosynthetic analysis) for each molecule. Include important reagents over the reaction arrows. 3. Provide a paragraph where you explain how each of the chemical reactions required for ONE of the two syntheses will be carried out. The conditions for each step and anticipated purification procedures must be included. You will write up a short paper (no more than 400 words) including 1) the two retrosynthetic and synthetic schemes and 2) A short paragraph outlining the conditions for each step. (One short paragraph per step). The example below is for a similar exercise. Note that the aldol/Claisen target is based on five-carbon alkyl bromides rather than the 4-C starting materials that are specified in your assignment.