Ether Complexes R ·Grignard reagents O-R H H-C一Mg-X H H R—O8 ·Electrophiles :OtB二H R H BH3·THF ·Crown ethers 18-crown-6 Chapter 14 with K+solvated 7 Chapter 14 7 Ether Complexes • Grignard reagents • Electrophiles • Crown ethers O B H H H + _ BH3 THF =>