Synthesis, regioselective hydrogenolysis, partial hydrogenation, and conformational study of dioxane and dioxolane-type (9'-anthracenyl)methylene acetals of sugars

Carbohydr Res. 2009 Dec 14;344(18):2444-53. doi: 10.1016/j.carres.2009.09.007. Epub 2009 Sep 12.

Abstract

Dioxane-type (9'-anthracenyl)methylene acetal of methyl 2,3-di-O-methyl-alpha-D-glucopyranoside was cleaved with LiAlH(4)/AlCl(3) (3:1) or with Na(CN)BH(3)-HCl regioselectively to provide the 4- or 6-O-(9'-anthracenyl)methyl ether, respectively. Hydrogenolytic reaction of the exo and endo isomers of dioxolane-type acetals proved to be directed by the configuration of the acetalic carbon as well as by the intramolecular participation of the adjacent-free hydroxyl; ring-opening reaction of the endo isomer of the methyl 2,3-O-(9'-anthracenyl)methylene-alpha-L-rhamnopyranoside took place with complete selectivity resulting in the axial (9'-anthracenyl)methyl ether, whereas a 1:1 mixture of the axial and equatorial ethers was formed upon the same reaction of the exo isomer. Catalytic hydrogenation of the sugar acetals resulted in (9',10'-dihydro-9'-anthracenyl)methylene derivatives without affecting the acetalic center. High-temperature molecular dynamics simulations and DFT (Density Functional Theory) geometry optimizations were carried out to study the conformation of the dioxane-type (9',10'-dihydro-9'-anthracenyl)methylene acetal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetals
  • Carbohydrates / chemistry*
  • Dioxanes / chemistry*
  • Dioxolanes / chemistry*
  • Hot Temperature
  • Hydrogenation
  • Molecular Conformation
  • Molecular Dynamics Simulation

Substances

  • Acetals
  • Carbohydrates
  • Dioxanes
  • Dioxolanes
  • formal glycol