ABSTRACT
In this chapter, we will be considering how the relationship between two functional groups in a molecule can direct us to a possible disconnection. We will study 1,2-, 1,3-, 1,4-, 1,5-, and 1,6-difunctionalized compounds. In general, we will consider how to make 1,x-dioxygenated compounds because there are more routes for this-but we remember that these may be readily converted into other functionalities. We will ƒnd that 1,3-dioxygenated compounds are readily prepared via the carbonyl condensation reactions that we met in Chapter 17 and that 1,5-dioxygenated compounds are prepared by the related conjugate addition reactions. ese are sometimes described as natural disconnections-they reÁect what the molecule “would like to do.” e syntheses of 1,2-, 1,4-, and 1,6-difunctionalized molecules require quite di…erent techniques, using what are sometimes referred to as illogical disconnections, or the use of unnatural nucleophiles. E…ectively, we will trick the molecule into a particular reaction.
