Then write complete synthetic paths, including reagents and reaction conditions based on your retrosynthetic analyses. Full Retrosynthetic Analysis for the synthesis of 3-ethylmethylhexanol Starting materials in bold H O b. Introduction: The retrosynthetic approach to organic synthesis starts from the product and attempts to determine what reactant molecules might be used to synthesize the target molecule The desired product in one reaction step. Thus, most reactions correspond to the following disconnection: Example 1 1st decision — which bond to disconnect first! Compare each of these features to the final product.
For the initial free-radical halogenation of the alkane, we have the option of chlorine Cl2 or bromine Br2. Once you have all of your intermediates drawn in from product to reactant, quickly follow the sequence from reactant to product to ensure it looks right and makes sense. Now we treat the alkene as our new product and ask the same question again.
The carbon chain doubles in size indicating an acetylide SN2 reaction with an alkyl halide. Freeman and Company, McMurry, John. The substituents have an ortho relationship. Make careful note of anything that changes because our goal in carrying out retrosynthesis will be exactly that: figuring out HOW to carry out these transformations, which brings me to question 2. In some cases, biological enzymes can accomplish this. These same thoughts can be applied to any retrosynthesis problem from two through steps and more.
Simple Multi-Step Syntheses A one or two step sequence of simple reactions is not that difficult to deduce. For the initial free-radical halogenation of the alkane, we have the option of chlorine Cl2 or bromine Br2. O H Then write a complete synthetic path, including reagents and reaction conditions based on your retrosynthetic analysis. Retro-Synthesis Working forwards, we specify the reagents needed for each reaction. It can be helpful to build and design your own reaction maps for each functional group studied.
Because methylcyclohexane has several different classifications of carbons, the selectivity of Br2 is more important than the faster reactivity of Cl2. Alcohols are amphoteric; they can act both as acid or base.
Start with backwards thinking whenever you can. The reactant has a halogen at carbon 2. For our next lab discussion period, use retrosynthetic analysis to devise at least two syntheses for the following compounds. Alternative synthesis of Many ways to make alcohols e. Ask yourself this question one at a time as you fill in the reaction conditions and complete your retrosynthesis sequence.