Diastereoselective mukaiyama and free radical processes for the synthesis of polypropionate units.
[reaction: see text] Reported herein is the synthesis of 8 out of 16 polypropionates derived from our propionate units. A new strategy involving a stereoselective Mukaiyama aldol reaction followed by a stereoselective free-radical-based hydrogen transfer, both under Lewis acid control, is used. Of particular interest is the remarkable reactivity of (i-PrO)TiCl(3) in this context to give only the 3,4-anti bromoesters.
Guindon
Yvan
Y
Institut de recherches cliniques de Montréal (IRCM), Bio-organic Chemistry Laboratory, 110 avenue des Pins Ouest, Montréal, Québec, Canada. guindon@ircm.qc.ca
Brazeau
Jean-François
JF