Download PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Novel fused heterocycles 1,10-dioxa-cyclopenta[a]fluorene and benzo[b]naphtho[2, 1-d]furans were synthesized via Dötz intramolecular benzannulation of alkyne tethered aryloxy chromium Fischer carbenes. ... Novel fused heterocycles 1,10-dioxa-cyclopenta[a]fluorene and benzo[b] ...