ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Saponification of homodiazepine 1a and 1b, in the absence of any proton donors, led to the formation of the 6π electron anionic species A which, by virtue of a 1,5-electrocyclization, is in equilibrium with the allylic anion B. This latter tricyclic species is thermodynamically less favoured than its bicyclic isomer A. Nevertheless, B could be trapped by acylation and led tupe-2 compounds which are the major reaction products. This is due to the fact that B is more nucleophilic and, therefore, much more reactive than A. The transoid topology of the tricyclic products 2 was demonstrated by 1H-NMR and by an X-ray diagram of 2d. The transoid geometry of 2 is a consequence of a torquospecific 1,5-electrocyclization (of A), which is due to a steric, and possibly even to an electronic factor.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19870700814
