Retro synthesis

retro synthesis

1. Retro synthesis

2. Organic synthesis The preparation of a desired organic compound from a readily available starting material is known as organic synthesis. Synthesis- Singular Syntheses - Plural

3. Compound which we wish to prepare is called a desired organic compound. Hetero atoms are more electronegative O,Br,Cl,I etc. partial positive charge appears on carbon [+] Si, Mg, Li are electropositive compound with the carbon, The polarity in this case is reversed partial negative charge on carbon [-]

4. Ideal synthesis Environment acceptance Avoidance of problematic waste [ Green Route ] Avoidance of toxic intermediate [ The Healthiest route ] Atom economy

5. Safe- avoidance of risk procedure. Economically acceptable Cost of materials –the cheapest route Novelty – the patent route Robust- Easily scale up reproducibility. High efficient – Simple, high yield, a few steps.

6. The exercise of organic synthesis require Knowledge of reactivity [ structure, Mechanism] Design ability [ Retro synthetic Analysis]

7. The ultimate goal of organic synthesis is to assemble an organic compound from readily available starting material and reagents in the most efficient way. This process usually begins with the design of a synthetic plan.

8. Retro synthesis The process of working backward from target molecule in order to device suitable synthetic route. Or The process of mentally breaking down a molecule into a starting material.

9. Need for retrosynthesis To attain shorter synthesis path for the target . To increase yield of the process by choosing another synthesis strategy.

10. Arrow notations used

11. Disconnection It is a paper operation involving an imagined cleavage of bond. As a result of disconnection, usually positive and negative ion are formed which are called synthons. It is shown by wavy line Or zigzag line

12. Disconnection

13. Functional Group Interconversion Process of writing one functional group for another to help synthetic planning is known as Functional Group Interconversion. It can be achieved by addition, substitution, elimination, oxidation, reduction and free radical reaction.

14. Synthons are idealized fragments. Synthons are shown by a + or – like anion or cation but not the real anion or cation. Synthetic equivalent is denoted by a Is known as REAGENT

15. Rules for Disconnections The hardest task in designing a retrosynthetic analysis is spotting where to make the disconnection. Disconnection must correspond to known reliable reactions and it is the most important thing to bear in mind when working out a retro synthesis.

16. For compounds consisting of two parts joined by hetero atom, disconnect next to the hetero atom.