Synthesis of planar-chiral paracyclophanes via samarium(II)-catalyzed intramolecular pinacol coupling.
[reaction: see text] A series of [n]paracyclophanediols (n = 8-12) was synthesized by samarium-catalyzed pinacol coupling for their ansa-bridge formation. Enantiomerically pure [n]paracyclophane esters were derived from the diols in a several steps via chiral resolution (for n = 10) or via crystallization-induced asymmetric transformation (for n = 11) by using amino alcohol auxiliaries and their selective cleavages.
Ueda
Tsuyoshi
T
Department of Industrial Chemistry, Meiji University, Tama-ku, Kawasaki 214-8571, Japan.
Kanomata
Nobuhiro
N
Machida
Hajime
H