Ring Enlargement of the β-Lactam Nucleus of Penicillins
摘要:
AbstractUsing penicillins as starting materials, a general synthetic route to the bicyclic compounds 7 has been established; they formally result from a ring enlargement of the ß‐lactam with insertion of one nitrogen atom. The key‐step of the procedure is a very mild Lossen rearrangement of hydroxamic acids intermediates upon treatment with N,N‐diethylaminopropyne.
THE USE OF LIPOPHILIC BETA-LACTAM ANTIBIOTICS AND CARBOXYLATE ESTERS FOR THE TREATMENT OF BACTERIAL INFECTIONS WITHIN CITRUS AND OTHER PLANT SPECIES
申请人:BOARD OF REGENTS OF THE NEVADA SYSTEM OF HIGHER EDUCATION ON BEHALF OF NEVADA
公开号:US20200230114A1
公开(公告)日:2020-07-23
Disclosed is method for converting a beta-lactam antibiotic into a “masked” beta-lactam antibiotic to permit it to cross the waxy cuticle of a plant and then subsequently unmasking the beta-lactam and converting it into an active beta-lactam antibiotic in the plant phloem. The method permits the use of beta-lactam antibiotics to be used to treat a variety of plant bacterial infections that was not previously possible because the native beta-lactam antibiotics cannot cross the waxy cuticle of plants. In one embodiment the disclosure finds special use in the treatment of bacterial infection of citrus plants with Huanglongbing disease.
Ring Enlargement of the β-Lactam Nucleus of Penicillins
作者:J. Marchand-Brynaert、L. Ghosez
DOI:10.1002/bscb.19850941123
日期:——
AbstractUsing penicillins as starting materials, a general synthetic route to the bicyclic compounds 7 has been established; they formally result from a ring enlargement of the ß‐lactam with insertion of one nitrogen atom. The key‐step of the procedure is a very mild Lossen rearrangement of hydroxamic acids intermediates upon treatment with N,N‐diethylaminopropyne.
Synthesis of pivaloyloxymethyl esters of penicillins and their conversion to deacetoxycephalosporins
作者:L. S. Povarov、D. A. Shostak、E. Ya. Zinchenko
DOI:10.1007/bf00764296
日期:1976.1
attention uses the trichloroethyl [I] and p-nitrobenzyl [3] esters of benzyl and phenoxymethyl penicillin sulfoxides. One of the defects of these methods is the difficulty of removing the ester-protecting groups from the carboxyl group in the final product. Hence, it was of interest to investigate the use of other peniCillin esters for the transformation, esters which would either split more readily or