1. β-D-glucopyranose in cyclohexane projection. This is a D-aldose in the open chain form, and is clearly a hexose.
  2. Arbutin is the glycoside formed from α-D-glucopyranose and quinol.

    Quinol.

    Glucose.

  3. Verbascose consists of three α-1→6 linked galactose units α-1→6 linked to a glucose moiety, β-1→4 linked to fructose. Verbascose is a sucrose with a short galactan 'tail'.

    Verbascose.

  4. They are the same molecule: reduction of the carbonyl group will yield two identical molecules (you may need to turn 'L-gulitol' upside down to see this). D-glucitol is the preferred name (although it is generally called 'sorbitol' by biologists).

    D-glucose.
    D-glucose

    L-gulose.
    D-gulose

    D-sorbitol
    D-glucitol