Synthesis of spirocyclic C-arylglycosides and -ribosides by ruthenium-catalyzed cycloaddition.
Spirocyclic C-arylglycosides were synthesized from the appropriately protected delta-gluconolactones. Addition of lithium acetylide followed by glycosylation with 3-(trimethylsilyl)propargyl alcohol converted the delta-gluconolactones into silylated diynes. After desilylation, subsequent ruthenium-catalyzed cycloaddition of the resultant diynes with alkynes or chloroacetonitrile gave spirocyclic C-arylglycosides in good yields and selectivity. This strategy was also extended to the synthesis of spirocyclic C-arylribosides from the known gamma-ribonolactone derivative. Moreover, silver-catalyzed iodination of the sugar diynes followed by ruthenium-catalyzed cycloaddition with acetylene delivered spirocyclic C-iodophenylglycosides and -ribosides, which were subjected to palladium-catalyzed C-C bond-forming reactions and copper-catalyzed coupling with nitrogen heterocycles to lead to various derivatives.
Yamamoto
Yoshihiko
Y
Department of Applied Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152-8552, Japan. omyy@apc.titech.ac.jp
Yamashita
Ken
K
Hotta
Tomitaka
T
Hashimoto
Toru
T
Kikuchi
Makoto
M
Nishiyama
Hisao
H
D002384:Catalysis; D003500:Cyclization; D006027:Glycosides / Q000138:chemical synthesis*; D007202:Indicators and Reagents / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry*
D006027:Glycosides; D007202:Indicators and Reagents; D012428:Ruthenium