SEQUENTIAL SYNTHESES THE TRANSITION FROM MACRO TO MICRO

The synthesis of a vast array—now numbering in the millions—of new organic molecules in academic and industrial laboratories over the past 100 years is one of the great achievements of modern science. Many of these new compounds have had profound effects on our way of life, both good and bad. A great challenge in the next century wlE be how society applies these powerful materials, and the new molecules yet to be bom, to the common good. 

Our ability to synthesize highly complex organic substances has taken a number of dramatic jumps during this century, and has resulted in a bewildering collection of substances that have been devised, synthesized, and applied to practically every facet of our lives. Many of these materials are now vital to our daily life (consider penicillin) and we all too often take them for granted. In just the last 30-40 years, new advances in pharmaceutical compounds have saved, extended, and made more comfortable the lives of hundreds of millions of people. The list could go on and on, including textiles, surfactants, plastics, and synthetic oils, to name only a few. 

Historically, the synthesis of complex organic substances was primarily driven by the need to obtain large quantities of biologically active material that occurred as the product of plant or animal metabolism, but that could be obtained only in very small quantities from nature. For example, the synthesis of the adrenal cortex hormone, cortisone, was a major breakthrough for hormone therapy. The synthesis of this material initially required 33 steps. That is, the research chemist carried out a sequence of 33 reactions in which stable isolable intermediates were formed sequentially, leading ultimately to the desired cortisone molecule. Industrial sequences of this length are now rare, but those requiring three to six steps are common. 

In this chapter we describe a set of six sequential experiments. These experiments vary in the number of intermediates that are required from seven to three, and they vary in the complexity of the chemistry, from straightforward extensions of Chapter 6 to relatively demanding experimentation similar to that described in Chapter lOW. 

The synthesis of piperonylonitrile is an example of a novel conversion, in three steps, of an aromatic aldehyde to an aromatic nitrile  

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SEQUENTIAL SYNTHESES THE TRANSITION FROM MACRO TO MICRO... 

CHAPTER 7 Sequential Syntheses The Transition from Macro to Micro... 

CHAPTER 7 Sequential Syntheses The Transition from Macro to Micro 7-61. Sulfonyl chlorides also react readily with alcohols to yield sulfonate esters ... 

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