Question

Ribose is a 5-carbon sugar molecule and an essential part of DNA and RNA. It has the following chemical structure as 6-membered ring: OH 1) Determine its sum formula: 2) Mass spectrum: what is the M* signal? 3) Name functional group A: 4) Name functional group B: 5) What is the approx. pka of functional group C: 6) Functional group A is a reaction of two entities. In this case the reagents are tethered and thus forming a ring. What at the two functional groups that react to form A: and, ii) 7) Determine R/S of stereo centre for D: 8) Draw the 3-dimensional chair configuration of the shown ribose molecule:

Answer 1

Ans: 1. Molecular Formula C₅H₁₀O₅

_2. The molecular weight of ribose is 150 Daltons the M+ signal is 151 and fragments 379, 103, ...so on

_{3. ester}

_{4. alcohol}

_{5.pka of functional group C is 11.31}

_{6. (i) aldehyde (ii) alcohol}

_{7. R is a stereocenter for D}

_8.

_{НО ОН но ОН THO н . - но -0, ин - и он -}