SYNTHESIS OF NOVEL ENYNE-ALLENES, THEIR THERMAL C-2-C-6 CYCLIZATION, AND THE IMPORTANCE OF A BENZOFULVENE BIRADICAL IN THE DNA STRAND CLEAVAGE

Novel enyne-allenes without acceptor substituents have been prepared f rom propargyl acetates by Pd-catalyzed addition of arylzine chloride o r by cuprate addition. Their thermal reaction afforded exclusively the C-2-C-6 and no Myers-Saito cyclization products. In one case, intermo lecular hydrogen abstraction and DNA strand cleavage were observed.