Stereo- and regio-controlled carbon–carbon bond formation mediated by tungsten in the s-trans-η<sup>4</sup>-diene cationic intermediates
作者:Ming-Huei Cheng、Yuung-Hsing Ho、Sue-Lein Wang、Chih-Yi Cheng、Shie-Ming Peng、Gene-Hsian Lee、Rai-Shung Liu
DOI:10.1039/c39920000045
日期:——
The tungsten-η3-2-substituted pentadienyl complexes WC5H5(CO)2(syn-η3-R-C5H6)(R = COOMe; CMeCH2) undergo BF3-catalysed stereoselective carbon-carbon bond formation with aldehydes to afford isolable s-trans-diene cations which after hydrolysis produces tungsten-η3-allyl-1,3-diols; utilization of the diols for stereoselective synthesis of α-methylene-γ-butyrolactones, furanone skeletons, have been reported in good yields (> 80%).