Total Synthesis of the Postulated Structure of Fulicineroside
作者:Ruben Bartholomäus、Fabian Dommershausen、Markus Thiele、Narayan S. Karanjule、Klaus Harms、Ulrich Koert
DOI:10.1002/chem.201204545
日期:2013.6.3
A totalsynthesis of the proposed structures of fulicineroside and its aglycone fulicinerine is reported. The tetrasubstituted dibenzofuran substructure was accessible either through a Pd‐mediated ortho‐metalation or by an Ir‐catalyzed meta‐borylation. The synthesis of the β,β,α‐linked trisaccharide consisting of D‐olivose, L‐rhodinose, and L‐rhamnose was challenged by the unprecedented β‐linked rhodinose
Synthesis of <scp>l</scp>-Daunosamine and <scp>l</scp>-Ristosamine Glycosides via Photoinduced Aziridination. Conversion to Thioglycosides for Use in Glycosylation Reactions
作者:Matthew T. Mendlik、Peng Tao、Christopher M. Hadad、Robert S. Coleman、Todd L. Lowary
DOI:10.1021/jo061167z
日期:2006.10.1
l-ristosamine glycosides is reported. Photoreaction of methyl 4-O-azidocarbonyl-2,3,6-trideoxy-l-hex-2-enopyranosides, followed by aziridine opening, leads to 3-amino-3-N-,4-O-carbonyl-2,3,6-trideoxy precursors to the aminosugar methyl glycosides. Conversion of these precursors to their thioglycoside analogues followed by N-acetylation of the carbamate moiety permits high yielding and, in some cases, stereoselective
The total synthesis of lactonamycin has been achieved. The synthesis includes sequential intramolecularconjugateaddition of alcohols to the acetylenic ester, stereoselective glycosylation of the tertiary alcohol, and Michael–Dieckmann type cyclization with the thioester, by which the highly convergent route has been established.
Regioselectivity in the Palladium-Catalyzed Addition of Carbon Nucleophiles to Dihydropyran Derivatives
作者:Marc-Raleigh Brescia、Yvonne Class Shimshock、Philip DeShong
DOI:10.1021/jo961973d
日期:1997.3.1
The regioselectivity of Pd-catalyzed malonate or sulfonylacetate addition to dihydropyran derivatives is highly dependent upon the substitution pattern of the dihydropyran nucleus and is governed by electronic, rather than steric factors. In certain instances, subtle steric features also play a role in controlling regioselectivity by altering the conformation of the intermediate eta(3)-allyl Pd-complex.