Affiliation:
1. Department of Chemistry National Taiwan Normal University 88, Sec. 4, Tingchow Road Taipei 11677 Taiwan, R.O.C.
Abstract
AbstractA strategy was developed for synthesizing furan‐fused dibenzotropones via intramolecular Wittig reactions of alkylidene dibenzo‐β‐tropolones and acylating reactants in catalytic or stoichiometric conditions. With these protocols, a series of furo[2,3‐f]dibenzotropones were obtained in 49–99% yields within 1–10 hours. Mechanistic studies of the base‐free phenomena revealed that the organophosphane acts both as a mediator and a regenerable Brønsted base under heating.