Alkoxymethyl radicals, generated conveniently from phenylseleno precursors, cyclize to afford substituted tetrahydrofurans and tetrahydropyrans in excellent yield and with good stereoselectivity.
Lewis acid-catalyzed three-component condensation reactions of aldehydes, alkoxysilanes, and allenylsilanes: synthesis of α-propargyl ethers
作者:Lui Niimi、Shuichi Hiraoka、Tsutomu Yokozawa
DOI:10.1016/s0040-4020(01)01145-0
日期:2002.1
Lewis acid-catalyzed reaction of acetals with allenylsilanes and the three-component reactions of aldehydes, alkoxysilanes, and allenylsilanes are described. Both reactions are strongly dependent on the substituent at the α-position of allenylsilanes. Allenylsilanes having bulky substituents such as the tert-butyl and isopropyl groups result in the corresponding α-propargyl ethers in high yields, whereas