| En route towards the synthesis of chlorine containing natural products, Strunz and Kabanyane recently communicated a short synthetic approach that provided a quick and efficient total synthesis of the fungal metabolite, dechlorocryptosporiopsin. Since in a biological assay, the biological activity of dechlorocryptosporiopsin appears to reside solely in the dextrorotatory enantiomer, an asymmetric synthesis was desired.; The stereochemistry in this route is first introduced by a [2+2] cycloaddition. Therefore the goal of the present research was to devise an efficient asymmetric [2+2] cycloaddition methodology that could be applied to the enantioselective syntheses of these chlorine containing natural products.; A complete asymmetric [2+2] cycloaddition methodology was developed using various chiral enol ethers with dichloroketene, which successfully led to the formal total synthesis of (−)dechlorocryptosporiopsin. A serendipitous discovery during this synthetic endeavor also led to the asymmetric formal total synthesis of another important chlorine containing natural product, (−)cryptosporiopsin. |
