TY - CHAP M1 - Book, Section TI - Stereochemistry A1 - Renslo, Adam A2 - Renslo, Adam PY - 2016 T2 - The Organic Chemistry of Medicinal Agents AB - In this chapter we will consider the stereochemistry of organic molecules, a topic that is concerned with how the atoms of a molecule are arranged in three dimensions. This is an important topic in pharmaceutical chemistry because the shape of a drug molecule affects both its desired biological activity and its potential for exhibiting undesired effects. To introduce the topic of stereochemistry, consider the three chemical drawings shown below (Figure 3.1). Each of these representations describes a six-membered carbon ring with two methyl groups attached at defined positions—all three drawings describe the molecule 1,3-dimethylcyclohexane. However, as one moves from the first to second drawing, additional important information is conveyed. Whereas the first drawing tells us only about the connectivity of carbon atoms, the second tells us about the relative orientation of the two methyl groups—one is projecting out of the plane of the paper whereas the other is receding behind it. This drawing describes a specific stereoisomer of 1,3-dimethylcyclohexane. An even more informative representation is provided in the third drawing, which tells us not only about the relative orientation of the methyl groups but also about the relative positioning of all the carbon atoms in the cyclohexane ring. This third drawing attempts to illustrate the actual three dimensional shape of 1,3-cyclohexane, including its conformation, a topic we will cover in detail in the following chapter. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessbiomedicalscience.mhmedical.com/content.aspx?aid=1124842336 ER -