Retrosynthetic analysis disconnections/synthons/synthetic

Retrosynthetic Analysis — One-Step Disconnections. For each of the following compounds, suggest a one-step disconnection. Use FGIs as needed. Show charge patterns, the synthons, and the corresponding synthetic equivalents. 

Retrosynthetic analysis involves the disassembly of a TM into available starting materials by sequential disconnections and functional group interconversions. Structural changes in the retrosynthetic direction should lead to substrates that are more readily available than the TM. Synthons are fragments resulting from disconnection of carbon-carbon bonds of the TM. The actual substrates used for the forward synthesis are the synthetic equivalents (SE). Also, reagents derived from inverting the polarity (IP) of synthons may serve as SEs. 

A useful step in a retrosynthetic analysis is a disconnection—breaking a bond to produce two fragments. Synthons are fragments of a discomiection. A synthetic equivalent is the reagent used as the source of the synthon. 

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