4-(Protected amino)-3-oxo-1-(substituted and unsubstituted methylene)-1,2-pyrazolidinium ylides are intermediates to 7-substituted bicyclic pyrazolidione antimicrobials.
Synthesis of a 3-keto bicyclic pyrazolidinone using a Curtius rearrangement
作者:David A. Neel、Richard E. Holmes、Jonathan W. Paschal
DOI:10.1016/0040-4039(96)01003-9
日期:1996.7
The synthesis of bicyclic pyrazolidinone 2 is described. Traditional methods for penem and cephem ring cyclization were found to be unsuccessful and new methodology using a Curtius rearrangement was utilized. The 3-enamine 11 was hydrolysed to the desired β-keto ester 2b without substantial loss of the t-BOC protecting group.
The chemistry of substituted pyrazolidinones; applications to the synthesis of bicyclic derivatives
作者:Robert J. Ternansky、Susan E. Draheim
DOI:10.1016/s0040-4020(01)88183-7
日期:——
Methodology for the selective chemical derivatizations of substituted pyrazolidinones is described. The application of these methods to the preparation of [4.3.0] and [3.3.0] bicyclic systems is also discussed. The importance of these latter systems as nuclei of antibacterial agents with potential utility in the treatment of infectious disease provides the motivation for these investigations.
Thioaldehydes in cycloaddition reactions. Synthesis of nuclear analogues of pyrazolidinone antibacterial agents
作者:Timothy A. Shepherd、Louis N. Jungheim
DOI:10.1016/s0040-4039(00)80679-6
日期:1988.1
generated thioaldehydes have been found to undergo 1,3-dipolarcycloadditions with a pyrazolidiniumylide to produce a nuclear analogue of pyrazolidinone antibacterialagents.
1,3-Dipolar cycloaddition reactions of pyrazolidinium ylides with vinyl sulfones. A regioselective synthesis of bicyclic pyrazolidinone antibacterial agents
作者:Louis N. Jungheim、Charles J. Barnett、Joseph E. Gray、Linus H. Horcher、Timothy A. Shepherd、Sandra K. Sigmund
DOI:10.1016/s0040-4020(01)85943-3
日期:1988.1
The 1, 3-dipolar cycloadditionreaction of pyrazolidinium ylide with substituted vinylsulfones was studied. Elimination of benzenesulfinic acid from the resulting cycloadducts gave rise to bicyclic pyrazolidinones . The (E)-olefin isomers were found to undergo cycloaddition in a highly regioselective fashion. These pyrazolidinones represent the nuclei of an exciting new class of potent antibacterial