Central to axial chirality transfer via double bond migration: asymmetric synthesis and determination of the absolute configuration of axially chiral 1-(3′-indenyl)naphthalenes

Abstract

(1R)-Menthyl (R)- and (S)-1-(1′-indenyl)naphthalene-2-carboxylates 3 and 4 are stereoselectively isomerised to the (1R)-menthyl (S)- and (R)-1-(3′-indenyl)naphthalene-2-carboxylates 5 and 6, respectively, on treatment with triethylamine, the relative configuration of 5 being established by a single crystal X-ray study; the sense of chirality transfer is reversed on LAH reduction of 3 and 4, stereoselectively furnishing (R)- and (S)-1-(3′-indenyl)naphthalene-2-methanol ent-7 and 7, respectively, via an intramolecular deprotonation reaction.