Synthesis of Organic Compounds: Solvent Selection and Side Reactions, Slides of Organic Chemistry

Download Synthesis of Organic Compounds: Solvent Selection and Side Reactions and more Slides Organic Chemistry in PDF only on Docsity! 1 Implementing Synthetic Strategies Considerations • From last class – Construction of carbon skeleton – Functional group conversions – Regiochemical control – Stereochemical control • New considerations – Solvent/Solubility – Side Reactions Solvent/Solubility • Many reagents are salts (soluble in/stabilized by polar solvents) • Many organic molecules are nonpolar (and NOT soluble in polar solvents) • Solution – Phase transfer catalysts: substances that are able to promote the transfer of salts into organic solvents docsity.com 2 Phase Transfer Catalysts Crown Ethers O O O OO O 18-crown-6 δ- δ- δ- δ- δ- δ- • Crown ethers present a hydrophobic outer surface, and thus dissolve easily in nonpolar solvents • Their internal cavity, however, is lined with partially negative oxygen atoms, which interact strongly with cations of the appropriate size • When cations are drawn into solution, the anions follow K+ Problem • What solvent might you choose for the following reactions, and which might require a phase-transfer catalyst? Br KCN CN OH H2Cr2O4 O docsity.com