
%0 Journal Article
%A Brown, RFC 
%A Fallon, GD 
%A Gatehouse, BM 
%A Jones, CM 
%A Rae, ID 
%T Synthesis of the cyclopropa[c]benzofuran system of mycorrhizin A and of gilmicolin from a benzofuranol. Crystal structure of a 5,8-Methanocyclopropa-[c]naphtho[2,3-b]furan derivative
%J Australian Journal of Chemistry
%D 1982/08/01
%V 35
%N 8
%P 1665-1678
%K 
%R https://doi.org/10.1071/CH9821665
%U https://www.publish.csiro.au/paper/CH9821665 
%X The cyclopropa[c]benzofuran derivative (17), which contains the structural features of methyl ethers of mycorrhizin A and gilmicolin save for the C3 side chain, has been synthesized from the benzofuranol (4) through the benzofuran-4,7-dione (5) and the 7a-methoxy derivative (8). The cyclopropane ring of (17) was introduced by ultraviolet irradiation of a 1-pyrazoline (13) at -78º; irradiation at room temperature gave mainly a profoundly rearranged acidic product for which the methanoindenone structure (18) is proposed. The stereochemistry of the penultimate cyclopropane (16) has been established by X-ray crystallography. 
