Chapter 13: Ethers and Thiols

Common name is constructed by: • Identifying each R group • Arrange them in alphabetical order • Add the word ether to the end of the word

Systematic name is constructed by: • Identify the larger group as the parent chain • Name the smaller group as an alkoxy substituent • Locants are assigned so as to give the lowest possible numbers

Use the formula X-crown-Y • X indicates the total number of atoms in the ring • Y represents the number of oxygen atoms

Reagents • NaH (sodium hydride) • RX Mechanism Starting with an alcohol as substrate, the hydride ion deprotonates the hydroxyl group with the alkyl halide subsequently attacking the negatively charged oxygen Alkyl halide must be a methyl or primary alkyl halide to favor SN2 reaction

Reagents • Hg(OAc)2 (mercuric acetate) & ROH • NaBH4 (sodium borohydride) Mechanism Markovnikov addition of an alcohol (RO and H) across an alkene; RO alkoxy substituent added to the more substituted vinylic carbon

Reagents excess HX (hydrogen halide) & heat Mechanism Ether is converted into two alkyl halides When a phenyl ether is cleaved under acidic conditions the products are an phenol and an ether; only applies to phenyls, NOT cyclic alkanes

Ethers undergo autooxidation in the presence of atmospheric oxygen to form hydroperoxides

Reagents RCO3H (peroxy acid) MCPBA or • Br2 & H2O • NaOH Mechanism Epoxides can be prepared using an alkene as a substrate upon treatment with a peroxy acid such as MCPBA or through a halohydrin intermediate

Reagents tBuOOH (tert-Butyl hydroperoxide) Ti[OCH(CH3)2]4 (titanium tetraisopropoxide) (+)-DET or (−)-DET Mechanism Enantioselective epoxidation process that produces only one enatiomer

Reagents • Stong Nuc • H3O+

Reagents HX (hydrogen halide) or H3O+ & H2O or H3O+ & ROH