Most complex natural products are chiral, and the bioactivity of chiral molecules varies with the enantiomer. This may lead to further modification of the process. Some syntheses are feasible on a research or academic level, but not for industry level production. Such applications involve major industries focused especially on polymers (and plastics) and pharmaceuticals. Total syntheses (see above) are sometimes used to showcase the new methodology and demonstrate its value in a real-world application. Finally, the researcher tries to extend the method to a broad range of different starting materials, to find the scope and limitations. Optimisation is a process in which one or two starting compounds are tested in the reaction under a wide variety of conditions of temperature, solvent, reaction time, etc., until the optimal conditions for product yield and purity are found. The discovery requires extensive knowledge of and experience with chemical reactivities of appropriate reagents. Methodology research usually involves three main stages: discovery, optimisation, and studies of scope and limitations. For practical applications, additional hurdles include industrial standards of safety and purity. To be useful, these methods need to give high yields, and to be reliable for a broad range of substrates. However, most intermediates are compounds that have never been made before, and these will normally be made using general methods developed by methodology researchers. A method may already exist in the literature for making one of the early synthetic intermediates, and this method will usually be used rather than an effort to 'reinvent the wheel'. ( March 2016) ( Learn how and when to remove this template message)Д®ach step of a synthesis involves a chemical reaction, and reagents and conditions for each of these reactions must be designed to give an adequate yield of pure product, with as few steps as possible. Unsourced material may be challenged and removed. Please help improve this article by adding citations to reliable sources. This section needs additional citations for verification. Some latter-day examples include Wender's, Holton's, Nicolaou's, and Danishefsky's total syntheses of the anti-cancer therapeutic, paclitaxel (trade name, Taxol). Robert Burns Woodward, who received the 1965 Nobel Prize for Chemistry for several total syntheses (e.g., his 1954 synthesis of strychnine ), is regarded as the father of modern organic synthesis. Convergent synthesis has the advantage of generating higher yield, compared to linear synthesis. For more complex molecules, a convergent synthetic approach may be preferable, one that involves individual preparation of several 'pieces' (key intermediates), which are then combined to form the desired product. Most often, each step in a synthesis refers to a separate reaction taking place to modify the starting compound. In a linear synthesis-often adequate for simple structures-several steps are performed one after another until the molecule is complete the chemical compounds made in each step are called synthetic intermediates. Total synthesis may be accomplished either via a linear or convergent approach. A total synthesis is the complete chemical synthesis of complex organic molecules from simple, commercially available petrochemical or natural precursors.

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