II. Advantages and Disadvantages of Sequential Reactions

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When two or more reactions occur in sequence, there is a savings in time, effort, and chemicals, compared to performing each reaction individually; therefore, sequential reactions can increase synthetic efficiency and provide a positive environmental impact by reducing chemical use.^3–5 An example of this efficiency is seen in the process pictured in Scheme 3, where two new rings form in a single reaction.⁶ There is a price to be paid for this efficiency. It comes in the form of the additional effort that usually is necessary in preparing the starting materials and establishing the reaction conditions so that each step in this more complicated process proceeds in the desired direction.^4,5 Not only may more synthetic work be required in substrate preparation, but controlling product regio- and stereochemistry also may be more challenging in a process where multiple structural changes occur in a single reaction.