Which of the following best defines total synthesis?

Total synthesis is best defined as the creation of complex molecules from simpler ones. This process involves taking basic chemical building blocks and assembling them into more complex chemical structures. It is particularly significant in organic chemistry, where chemists often seek to synthesize naturally occurring compounds, such as pharmaceuticals, that are notoriously difficult to extract or isolate from their natural sources.

In total synthesis, chemists utilize a variety of chemical reactions, techniques, and strategies to construct the target molecule step by step. The goal is to connect various simpler units through chemical reactions to form a final complex product that has specific desired properties.

While other options touch upon chemical processes, they do not accurately capture the essence of total synthesis. The breakdown of compounds into elements pertains more to decomposition reactions than to synthetic processes. The synthesis of a substance from elemental components only refers to a very specific and limited type of synthesis that does not encompass the broader context of creating complex molecules from simpler ones. Finally, the transformation of solids to gases relates to physical changes in state rather than the synthesis of chemical compounds, making it irrelevant to the definition of total synthesis.