SYNTHESIS AND OPTICAL RESOLUTION OF NAPHTHALENE-CONTAINING INHERENTLYCHIRAL CALIX[4]ARENES DERIVED BY INTRAMOLECULAR RING-CLOSURE OR STAPLING OF PROXIMAL PHENYL UNITS

New methods for the preparation of inherently chiral calix[4]arenes ha ve been developed. The molecular asymmetry in these calix[4]arenes is created by an asymmetrical disposition of naphthalene rings on the upp er rim, In compound 1, monoformylcalix[4] arene 5 was transformed into naphthalene-containing calix[4]arene by ring closure, In compound 2, p-chloromethyl groups are intramolecularly cross-linked with 3-hydroxy methyl-2-naphthol. This 'stapling reaction' results in a syn isomer 2a and an anti isomer 2b, the latter being classified into an inherently chiral calix[4]arene. Racemic anti 2 could be 'perfectly' optically r esolved by an HPLC method with a chiral-packed column. The chiral prod ucts were thoroughly characterized by various spectroscopic methods, T hese results indicate that the naphthalene skeleton is very useful for creating molecular asymmetry in calix[4]arenes.