An enantioselective approach to (-)-isoavenaciolide was achieved starting from 1-undecyn-3-ol. The synthesis relied upon the preparation of a chiral 4-silyloxy-2-alkenylborane by hydroboration of a protected 2,3-allenol and subsequent stereoselective addition to 2-thiophenecarboxaldehyde.
Efficient Synthesis of 3-Chloromethyl-2(5<i>H</i>)-furanones and 3-Chloromethyl- 5,6-dihydropyran-2-ones via the PdCl<sub>2</sub>-Catalyzed Chlorocyclocarbonylation of 2,3- or 3,4-Allenols
作者:Xin Cheng、Xuefeng Jiang、Yihua Yu、Shengming Ma
DOI:10.1021/jo8015677
日期:2008.11.21
was formed between the center carbon atom of the allene moiety and the hydroxyl oxygen, which was established by the X-ray single crystal diffraction study of gamma-lactone 3p. The highly opticallyactive 3-chloromethyl-2(5H)-furanones could be easily prepared from the readily available opticallyactive 2,3-allenols. A mechanism for this reaction was proposed.
Novel Substituent and Chelating Effects in the Pd-Catalyzed Reaction of 2,3-Allenols, Aryl Iodides, and Amines. Highly Regio- and Stereoselective Synthesis of 2-Amino-3-alken-1-ols or 4-Amino-2(<i>E</i>)-alken-1-ols