Mountain Scholar: Recent submissions
Now showing items 21-40 of 21704
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Synthetic and biosynthetic studies of the brevianamides
The preparation of a pinacol-type rearrangement precursor towards the total synthesis of target indoxyl 8 is presented. The route contains three key steps. These include a photooxidation reaction that installs a hydroxy ... -
Total synthesis of (+)-paraherquamide B, The
The first stereocontrolled total synthesis of (+)-paraherquamide B is described in 42 chemical steps. The synthesis is a convergent one, starting from S-proline and vanillin. Vanillin was acylated, nitrated and hydrolyzed ... -
Total synthesis of (+/-)-aspirochlorine, The
Aspirochlorine is a unique epidithiodioxopiperazine isolated from Aspergillus oryzae, Asp. tamarii and Asp. flavus. The molecule contains a highly unusual bicyclo [3.2.2]disulfide ring system which has previously never ... -
Asymmetric synthesis of amino acids via glycine enolates, The
The enolates derived from the optically active D-e rythro-4- (tertbutyloxycarbonyl)-5,6-di phenyl-2,3,5,6-tetrahydro-4H-1,4-oxazin-2-one (166a) and D- and L-erythro-4-(benzyloxycarbonyl)-5,6-diphenyl-2,3,5,6- tetrahydro- ... -
Asymmetric synthesis of arylglycines, The
The asymmetric synthesis of several arylglycines is discussed. Several methods for the coupling of an aromatic group to the chiral bromoglycinates (171, 172) were developed. It was found that the cuprate and Friedel-Crafts ... -
Asymmetric synthesis of amino acids via electrophilic glycinates, The
A new asymmetric synthesis of α-monosubstituted-α-amino acids using D- and L-erythro-4-benzy loxycarbonyl-5,6-diphenyl-2,3,5,6-tetrahydro-1,4-oxazin-2-ones 108 as amino acid templates is described. Bromination of 108 with ... -
Synthetic and pharmacophoric studies of quinocarcin
A new synthetic approach to the stereoselective total synthesis of the structurally unique antitumor antibiotic quinocarcin (1) is described. The utilization of model studies in this approach has led to novel methodologies ... -
Carbohydrates as chiral templates
Carbohydrates can serve as a source of functionalized asymmetric carbon atoms. The synthesis of a carbon fragment derived from 2-deoxy-glucose is described as an optically pure intermediate (34) for the synthesis of the ... -
Synthetic and DNA cross-linking studies of bioxalomycinα₂
The preparation of a [3 + 2] cycloaddition precursor towards the total synthesis of bioxalomycin α2 is presented. The route contains four key steps. These include a Staudinger reaction that sets the required syn stereochemistry ... -
Design and synthesis of analogs of the peptidylnucleoside antibiotics: the mureidomycins
The recent emergence of strains of bacteria which are resistant to many commercially available antibiotics requires a continual search for new drugs to combat infection. A new family of antibiotics, the mureidomycins, has ... -
Synthesis and study of bicyclomycin analogs
The synthetic utility of a key electrophilic coupling reaction developed in the total synthesis of bicyclomycin was explored in the hope that this methodology could be applied to the synthesis of homologs of this unique ... -
Part I. Asymmetric synthesis of 2,6-diaminopimelic acids (DAP) and γ-D(L)-glutamyl-L-meso-diaminopimelic acid dipeptide. Part II. Total synthesis of TAN-1057 and analogues
Part I. An asymmetric and stereochemically unambiguous construction of diaminopimelic acid and related system using the chiral, non-racemic diphenyl oxazinones glycinate templates has been developed. The preparations of ... -
Mechanism of action studies on the FR-9000482 class of antitumor antibiotics
The interactions of members of the FR-900482 class of antitumor antibiotic agents with DNA has been examined. Importantly, the first in vitro demonstration of nucleic acid interstrand cross-linking has been reported and ... -
Synthesis of a photo-activated analog of the antitumor antibiotic FR 900482
A novel synthetic route to the benzazocine framework of the antitumor antibiotic FR 900482 is presented. The synthesis of the benzazocine ring is characterized by a convergent asymmetric strategy. Although the benzazocine ... -
Studies toward the total synthesis of Fusarin C
The development of the synthesis of the heterocyclic proposed pharmacaphore of the natural mutagenic fungal metabolite fusarin C is discussed with the result of a short and elegant synthesis for this portion of the molecule. ... -
Synthesis of D-alanyl-D-alanine dipeptide isosteres and cephalosporin prodrugs
Resistance to vancomycin by enterococci is of great clinical importance. Vancomycin inhibits bacterial growth by binding to terminal D-alanyl-D-alanine linkages in the growing peptidoglycan cell wall. Synthesis of dipeptide ... -
Elucidating the biosynthetic pathway of taxol
The total synthesis of (±)-taxa-4(5),11(12)-diene, (±)-taxa-4(20),11(12)-diene, (±)-taxa-4(20), 11(12)-diene-5(β)-ol, and (±)-taxa-4(20),11(12)-diene-5(α)-ol is described. The syntheses rely upon selenium-based methodology ... -
Panning peptide libraries on filamentous phage
This Ph.D. project involved using the filamentous phage as a tool to express peptide libraries on its external appendage called the pIII protein. The peptide libraries were designed based on a motif of the honeybee toxin ... -
Preparation of azidobrevianamide A and synthetic and biological studies of tetrazomine
The regioisomers 5-azidobrevianamide A and 7-azidobrevianamide A were synthesized from natural (+)-brevianamide A. The synthesis involved nitration, reduction to the amine, formation of the diazonium ion, and reaction with ... -
Synthesis and biomechanistic studies of quinocarcin and structural analogs
The formal total synthesis of the antitumor antibiotic quinocarcin is presented. The synthesis is characterized by a novel NBS oxidative azomethine ylide cycloaddition reaction for the diastereoselective construction of ...
