CONFORMATION IN THE SOLID-STATE AND IN SOLUTION OF 21,22-TETRAHYDRO-7H,12H,19H,24H-DINAPHTHO-[1,8-F,G 1',8'O,P][1.4.10.13]TETRAOXACYCLOOCTADECIN/

The helical conformation of a new, optically active heterocyclic syste m 1 in solution has been determined from CD spectra by application of the exciton coupling theory. The molecule in the crystal adopts a conf ormation possessing an approximate 2-fold axis, with naphthyl groups n early coplanar. Absolute configuration at four chiral centres as deter mined unequivocally by Xray anomalous scattering method agrees with th e known configuration of the starting (R,R)-2,3-butanediol. The confor mations in the solid state and in solution are compared with those res ulting from AM1 calculations.