REGIOSELECTIVE RING-OPENING OF POLYCYCLIC AROMATIC HYDROCARBON EPOXIDES BY POLYMER-SUPPORTED N3- ANION

The benzylic ring opening of some polycyclic aromatic hydrocarbon (PAH) tetrahydro epoxides and one diol epoxide has been achieved by Amberlite supported N3-ion, in a regio- and stereoselective manner. The resulting azidohydrins have been converted to the corresponding β-acyloxy amines and/or amino alcohols. The β-acyloxy amino compounds are suitable for incorporation into synthetic oligonucleotides, whereas the amino alcohols were synthesized in order to establish the regiochemistry of the ring-opening step. The tetrahydro models studied were the naphthalene (Np), benz[c]acridine (BcAr), benzo[a]pyrene (BaP), and benzo[e]pyrene (BeP) epoxides. In the Np and BcAr cases, the amino group is equatorial whereas in the BaP and BeP cases, it is axial. In the final stage of these ring-opening reactions, the racemic diol epoxide of benzo[o]pyrene (BaPDE) 24 was converted to the corresponding amines. In each of the cases studied, the attack by N3-ion occurred at the benzylic site. The relative stereochemistry of the azido and hydroxyl groups in every case was trans. No other regio- or stereoisomer was observed in any of these compounds in the ring-opening step. © 1990, American Chemical Society. All rights reserved.