Asymmetric Synthesis of (−)-Pterocarine and (−)-Galeon via Chiral Phase Transfer-Catalyzed Atropselective Formation of Diarylether Cyclophane Skeleton

Pterocarine and galeon
are typical examples of diarylether heptanoids
(DAEHs) with planar chirality due to the strictly constrained conformations
in their molecular skeletons. The characterized oxa­[1,7]­meta­para-cyclo­phane
motifs in DAEHs impose great challenges for their enantioselective
synthesis. The asymmetric syntheses of (−)-pterocarine and
(−)-galeon are demonstrated by employing a chiral phase transfer-catalyzed
highly enantioselective SNAr cyclization as the key step
for the formation of a diarylether cyclophane skeleton.