Diastereoselective synthesis of 2,3,5-trisubstituted tetrahydrofurans via cyclofunctionalization reactions. Evidence of stereoelectronic effects.
The work described herein considers the impact of stereoelectronic effects and allylic 1,3-strain in controlling the cyclofunctionalization reaction when a hydroxyl group is at the allylic position. The stereoelectronic arguments are supported by independent iodocyclization reactions performed using two secondary alcohols. The transition-state pathways involved in these reactions are established through a comparison of relative reaction rates. A bi-directional approach is used to demonstrate the potential of the iodocyclization reaction to differentiate a terminus in molecules with a pseudo C(2) axis of symmetry, showing that two-directional synthesis can be used to differentiate between alternative transition-state pathways.
Guindon
Y
Y
Institut de recherches cliniques de Montréal (IRCM), Bio-organic Chemistry Laboratory, 110 avenue des Pins Ouest, Montréal, Québec, Canada H2W 1R7. guindoy@ircm.qc.ca
Soucy
F
F
Yoakim
C
C
Ogilvie
W W
WW
Plamondon
L
L