@article{Exner:171732,
      title = {Total Asymmetric Syntheses of beta-Hydroxy-delta-lactones  via Umpolung with Sulfur Dioxide},
      author = {Exner, Claudia J. and Laclef, Sylvain and Poli, Florent  and Turks, Maris and Vogel, Pierre},
      journal = {Journal Of Organic Chemistry},
      volume = {76},
      pages = {840-845},
      year = {2011},
      abstract = {Cyclic stereotriads and stereotetrads of the  beta-hydroxy-delta-lactone type, e.g. prelactones B and E,  common in polyketides and polypropionates, are prepared via  SO2-induced oxyallylations of enoxysilanes with  (1E,3Z)-1-(1-phenylethoxy)penta-1,3-dien-3-yl carboxylates.  Using (Z)- or (E)-enoxysilanes both 4,5-cis- or  4,5-trans-delta-lactones are obtained. Depending on the  reduction method applied to the obtained aldol  intermediates 5,6-trans or 5,6-cis-derivatives are formed.  The delta-lactones can be prepared in both their  enantiomeric forms depending on the (1R)- or  (1S)-configuration of the starting  1-(1-phenylethoxy)penta-1,3-dienes.},
}