ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
In search of new types of semisynthetic derivatives of the natural antibiotic rifamycin S (1), we synthesized 25-O-deacetyl-27,28-didehydro-27-demethoxy-11-deoxo-11,29-epoxy-28, 29-dihydro-21,23-O-isopropyli-denerifamycin S (3). Its X-ray crystal structure shows a new type of ansa-chain with an 11,29-epoxy moiety, the loss of the MeO group on C(27), and the shift of the C=C bond from C(28),C(29) to C(27),C(28). These modifications result in a conformational rearrangement of the whole ansa-chain, nonetheless the overall spatial shape of the molecule is still close to that of most rifamycins. As found in other 11-deoxo-11-hydroxyrifamycin-S derivatives, the chromophore rings of 3 give rise to π-π association in the crystal.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19920750112