Synthesis of long-chain polyketide fragments by reaction of 1,3-dioxy-1,3-dienes with allylsilanes: umpolung with sulfur dioxide.
[reaction: see text] In the presence of a Lewis or protic acid and at low temperature, 1,3-dioxy-1,3-dienes add to sulfur dioxide generating zwitterionic intermediates that can react with carbon nucleophiles such as allylsilanes. After a retro-ene elimination of SO(2), valuable polyketide precursors are obtained.
Turks
Māris
M
Institute of Molecular and Biological Chemistry, Swiss Federal Institute of Technology (EPFL), BCH CH-1015 Lausanne, Switzerland.
Fonquerne
Freddy
F
Vogel
Pierre
P