Nucleophilic Substitution and Retrosynthetic Analysis

Example Prepare (CH3)2CHCH2SH from any hydrocarbon and inorganic materials of your choice. 

Begin by writing a structural formula for the desired compound and select a bond that must be made, then disconnect that bond in a way related to a synthetic transformation. One possibility is  

The problem specifies that a hydrocarbon be the starting material, so hydroboration-oxidation of an alkene is a reasonable possibility for completing the retrosynthesis. 

With the retrosynthesis as a guide, we write the sequence of reactions in the forward direction and show the necessary reagents. 

Many different syntheses can often be devised, so it is important that each be evaluated critically to ensure that they meet the standards of regio- and stereoselectivity the target requires. 

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