76491-08-2Relevant articles and documents
Synthesis of the BCD-ring of ciguatoxin 1B using an acetylene cobalt complex and vinylsilane strategy
Kira, Kazunobu,Hamajima, Akinari,Isobe, Minoru
, p. 1875 - 1888 (2007/10/03)
Synthesis of the tricyclic BCD-ring segment with high stereoselectivity has been achieved starting from a sugar derivative directed toward the synthesis of the left part of ciguatoxin 1B. The central reactions in the synthesis are (i) ether ring formation mediated by an acetylene cobalt complex, (ii) decomplexation of the endo-acetylene cobalt complex to the vinylsilane, and (iii) ring-opening reaction of the epoxysilane into the allylic alcohol.
Regio- and stereoselective synthesis of β-D-gluco-, α-L-ido-, and α- L-altropyranosiduronic acids from Δa4-uronates
Bazin, Helene G.,Wolff, Michael W.,Linhardt, Robert J.
, p. 144 - 152 (2007/10/03)
The stereoselective synthesis of β-D-glucopyranosiduronic, α-L- idopyranosiduronic, and α-L-altropyranosiduronic acids has been performed from different Δ4-uronate monosaccharides. Bromination of the C-4,5 double bond provided the trans-diaxial bromohydrin derivatives, which were converted to the corresponding epoxides in high yields. Direct reduction of the epoxides using boranetetrahydrofuran complex led to the corresponding glucuronic acids in low to good yields. Glucuronic acids were also obtained in satisfactory yields through a two-steps procedure involving bromination of the epoxide with titanium(IV) bromide followed by reduction using tributyltin hydride. Lewis acid-catalyzed rearrangement of these epoxides led to the corresponding α-L C-4 ketopyranosides adopting the 1C4 chair conformation. Hydride reduction afforded the α-L-idopyranosiduronic or the α-L- altropyranosiduronic acids, the stereoselectivity of the reduction being controlled by the appropriate substitution pattern.
PREPARATION OF MIXED-ACETAL DERIVATIVES OF CARBOHYDRATES BY ACETAL-EXCHANGE REACTION
Liptak, Andras,Fuegedi, Peter,Kerekgyarto, Janos,Nanasi, Pal
, p. 225 - 232 (2007/10/02)
Acetal-exchange reactions of 2,3-disubstituted gluco- and galacto pyranoside derivates with acetone dimethyl acetal and acetophenone dimethyl acetal gave the 6-O-(methoxydimethyl)methyl and the 6-O-(methoxymethylphenyl)methyl derivatives as the kinetic pr