ABSTRACT
A number of highly functionalized dioxocyclams with acetic acid side chains on the secondary amine sites and ethylene glycol side chains on 6 and 13-positions (12a, 12b) or a tetra(ethylene glycol) side chain linking the 6 and 13 positions (15) were synthesized and characterized, as was a bis-dioxocyclam bridged across the 6 and 13 positions by tetra(ethylene glycol) groups (16). These were screened for their ability to complex Gd3+. Only ligands 15 and 16, having tetra(ethylene glycol) groups, formed such complexes.
Subject(s)
Gadolinium/chemistry , Heterocyclic Compounds/chemical synthesis , Polyethylene Glycols/chemistry , Acetylation , Cations , Crystallography, X-Ray , Esters/chemical synthesis , Ligands , Molecular Structure , Organometallic Compounds/chemical synthesisABSTRACT
Both tri- and tetra(ethylene glycol) linked bis-chromium carbene complexes have been synthesized. These carbene complexes were photolyzed with N-protected imidazolines to give protected azapenams. These were transformed into polyether-linked basket dioxocyclams 4a,b and bis-dioxocyclams 5a,b. These compounds have cavities for the complexation of both "hard" and "soft" metal ions. The complexes of Ni, Ba, and Gd were synthesized.
Subject(s)
Chelating Agents/chemical synthesis , Organometallic Compounds/chemical synthesis , Polyethylene Glycols/chemical synthesis , Acetylation , Barium/chemistry , Chelating Agents/chemistry , Chromium/chemistry , Crystallography, X-Ray , Magnetic Resonance Spectroscopy , Molecular Conformation , Nickel/chemistry , Organometallic Compounds/chemistry , Polyethylene Glycols/chemistrySubject(s)
Adenosine/analogs & derivatives , Antibiotics, Antineoplastic/chemical synthesis , Antiviral Agents/chemical synthesis , Furans/chemistry , 4-Butyrolactone/analogs & derivatives , Adenosine/chemical synthesis , Adenosine/chemistry , Antibiotics, Antineoplastic/chemistry , Antiviral Agents/chemistry , Indicators and Reagents , Molecular Conformation , StereoisomerismABSTRACT
Functionalized cyclopentenones were synthesized by the diazomethane ring expansion of cyclobutanones, produced by the photochemical reaction of vinyl oxazolidinones with chromium carbene complexes.
Subject(s)
Anti-Infective Agents/chemical synthesis , Cycloparaffins/chemical synthesis , Molecular Conformation , StereoisomerismABSTRACT
A novel, one-pot ring-expansion procedure was developed using Me3S(O)I, NaH, and Sc(OTf)3. The scope and limitations were briefly examined, and a tentative mechanism was proposed. Application of the methodology to known cyclobutanone 1 provided the corresponding cyclopentanone, which was successfully advanced to (+)-carbovir and (+)-aristeromycin.