Synthesis of methyl-substituted lariat ethers containing a 13-crown-4 ring

Convenient synthetic procedures for preparing two kinds of methyl-substituted lariat ethers containing a 13-crown-4 ring, 1 and 2, are described. Compounds 1a-1c were obtained from the reaction of 2-bromomethyl-2-methyl-13-crown-4 (5) with the appropriate alkoxide. Compound 5 was prepared without the need for prior protection of the bromomethyl group. For the synthesis of compounds 2a-2c, which possess an electron-donating group on the central carbon of the trimethyl moiety of the 13-crown-4 ring, the substituents were introduced before cyclization.