Internal Nucleophilic Termination in Acid-Mediated Polyene Cyclizations. Part 3
作者:Roger L. Snowden、Jean-Claude Eichenberger、Simon Linder、Philippe Sonnay
DOI:10.1002/hlca.200490155
日期:2004.7
Treatment of the unsaturated allenic alcohols (E)-7, (Z)-7, 10, 13, and 19 with an excess of FSO3H in 2-nitropropane at −90° to −30° afforded, in 68–85% yield, diastereoisomer mixtures of racemic tricyclic ethers 14a–d and 20a–d, respectively (Schemes 3 and 5), with high stereoselectivity (see Table and Scheme 6). These stereospecific transformations represent the first reported examples of an acid-mediated