Preparation of 6-epi-ampicillin and of 6-epi-.ALPHA.-hydroxybenzylpenicillin.
نویسندگان
چکیده
منابع مشابه
Applications of Epi-Retractable and Co-Epi-Retractable Modules
A module M is called epi-retractable if every submodule of M is a homomorphic image of M. Dually, a module M is called co-epi-retractable if it contains a copy of each of its factor modules. In special case, a ring R is called co-pli (resp. co-pri) if RR (resp. RR) is co-epi-retractable. It is proved that if R is a left principal right duo ring, then every left ideal of R is an epi-retractable ...
متن کاملErratum: Applications of epi-retractable and co-epi-retractable modules
In this errata, we reconsider and modify two propositions and their corollaries which were written on epi-retractable and co-epi-retractable modules.
متن کاملAsymmetric syntheses of 1-deoxy-6,8a-di-epi-castanospermine and 1-deoxy-6-epi-castanospermine.
Asymmetric syntheses of both 1-deoxy-6,8a-di-epi-castanospermine and 1-deoxy-6-epi-castanospermine, polyhydroxylated indolizidine alkaloids that act as selective glycosidase inhibitors, have been accomplished in seven steps. The key feature of our unique syntheses includes the stereoselective introduction of the C-3 and C-4 hydroxyl groups utilizing the aza-Claisen rearrangement-induced ring ex...
متن کاملApplications of epi-retractable modules
An R-module M is called epi-retractable if every submodule of MR is a homomorphic image of M. It is shown that if R is a right perfect ring, then every projective slightly compressible module MR is epi-retractable. If R is a Noetherian ring, then every epi-retractable right R-module has direct sum of uniform submodules. If endomorphism ring of a module MR is von-Neumann regular, then M is semi-...
متن کاملPreparation of 7-epi-cephalosporin derivatives.
position 6,1-4) the preparation of 7-epi-aminocephalosporanic 'acid (7a-ACA) has thus far not been reported. Some 7-epi-cephalosporins have been prepared by base-catalyzed epimerization of cephalosporin sulfoxidesu or acidcatalyzed ring expansion of 6-epi-penicillins.e) Both procedures, however, are not convenient for the preparation of 7-epi-cephalosporin derivatives. We wish to report the direct
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ژورنال
عنوان ژورنال: The Journal of Antibiotics
سال: 1977
ISSN: 0021-8820,1881-1469
DOI: 10.7164/antibiotics.30.847