
%0 Journal Article
%A Paddon-Row, MN 
%A Patney, HK 
%A Pasupuleti, LN 
%T An improved approach to benzene annelation: the synthesis of 11-substituted octahydro-1,4:9,10-dimethanoanthracenes and a study of OH&#8230;p bonding in these systems
%J Australian Journal of Chemistry
%D 1982/02/01
%V 35
%N 2
%P 307-317
%K 
%R https://doi.org/10.1071/CH9820307
%U https://www.publish.csiro.au/paper/CH9820307 
%X A procedure for benzene annelation, which incorporates the best features of previously reported techniques, is described and is applied to the synthesis of a series of 11-substituted octahydro-1,4:9,10-dimethanoanthracenes (1a-e). Thus addition of 1,2,3,4-tetrachloro-5,5-dimethoxycyclopentadiene(7) to (1&#946;,4&#946;, 4a&#945;, 5&#945;, 8&#945;, 8a&#945;)-anti-9-acetoxy-1,2,3,4,4a,5,8,8a-octahydro-1,4:5,8-dimethanonaphthalene(4b) gave the adduct (8b).* Deacetalization of (8b) followed by thermal, cheletropic loss of CO and subsequent base-induced dehydrochlorination gave the 5,6,8-trichlorooctahydro-1,4:9,10-dimethanoanthracen-anti-11-ol (17b) which could easily be converted into (1c) by using sodium and ethanol. Infrared and 1H n.m.r. studies revealed the presence of a strong intramolecular OH&#8230;&#960; bond in the syn-alcohol (1e). The observation of an unusually large vicinal coupling constant, J(HCOH) 12 Hz, for (1e) implies that the H-C-O-H exists in the antiperiplanar conformation which also maximizes the strength of the OH&#8230;&#960; bond. 
