2008 年 66 巻 2 号 p. 139-147
2-Bromo-1-alkenes have been recognized as one of useful functional groups for preparation of vinyl lithiums and vinyl Grignard reagents, for coupling partners in a wide range of transition metal-mediated coupling reactions, substrates of radical reactions, and precursors of a-haloke-tones. Selective elimination reaction of 1, 2-dibromoalkanes possessing aryloxy or acyloxy groups at the C 3 position into 2-bromo-1-alkenes under mild basic conditions was developed. Alkyne units are also one of the important functional groups for substrates of C-C coupling reactions. During our extensive investigation, the acidity enhancement of hydrogen at the C 1 position by oxygen-functional groups at the C 3 position was also observed. This observation indicated a new prospective synthesis of propargyl ethers from 1, 2-dibromoalkanes using DBU as a base. As application of these elimination reactions, total synthesis of biologically active natural products was accomplished.