In:
European Journal of Organic Chemistry, Wiley, Vol. 2007, No. 1 ( 2007-01), p. 88-100
Abstract:
Intense scale‐up efforts greatly improved the availability of the known double‐stranded cycle 2 with two bridging ether units. The chemistry of 2 towards Bronsted and Lewis acids could, therefore, be investigated quite comprehensively. It was discovered that the reactivity of 2 , whose carbon framework resembles the belt region of the C 84 ( D 2 ) fullerene, is rather unusual as compared with acyclic model compounds. Whereas the latter could easily be dehydrated to the corresponding planar arenes, the former gave rise to a bouquet of unexpected reactions, which all avoided the aromatization of 2 to its still‐elusive, fully conjugated congener B . Intermediates generated from 2 under acidic conditions attack the solvent (e.g. toluene) to give 4 , form bridging lactones to give 11 or close back to starting material 2 (e.g. from 16 ) rather than dehydrate to more highly conjugated structures on the way to the fully unsaturated target cycle B . The structure of compound 4 was solved by X‐ray diffraction. Through the reactions of 2 with Lewis acids, derivatives 14 and 15 became accessible. They are candidates for future attempts to achieve the desired aromatization under basic conditions or by thermal treatment. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Type of Medium:
Online Resource
ISSN:
1434-193X
,
1099-0690
DOI:
10.1002/ejoc.v2007:1
DOI:
10.1002/ejoc.200600698
Language:
English
Publisher:
Wiley
Publication Date:
2007
detail.hit.zdb_id:
1475010-7
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