Question

Chapters 21 and 22: 1. Consider the structure shown on the right and answer the following questions about it (ill in blanks or cirele proper choice) (4 a. Its molecular formula is G ,H( )0( , and so it fits the CHOH , general formula for a carbohydrate, which is b. Specifically, this structure is (a D/ an L) (aldo/keto) (pent/hex) (aselose) c. Will it be optically active? d. If the top carbon was converted to a CH,OH, would it be optically active? e. This molecule can form a six membered ring by addition of one of its -OH groups to the O-O group. Draw a circle around the-OH group which would lead to this ring. This is called a (furanose/pyranose) ring Draw the structure of this ring in the space on the right. six member ry fonm f. This molecule can also form a five membered ring by addition of one of its -OH groups to the C-O group. Draw a square around the -OH group which would lead to this ring. This is called a (furanose/pyranose) ring. g. In each of the rings referred to in parts e and f the carbonyl carbon has beern carbon. Draw a circle around this carbon converted into a hemi in your ring structure in part c. Draw in your ring structure in h. As the rings in parts e and f form, the C-O group yields a new chiral center which is called the omeric carbon. This new chiral center has an -OH group which is typically drawn either up or down in its cyclic form. The "up form is called (α / p) and the down form is called (α / β). In the polysaccharide starch, the the linkages from one saccharide to another are all (a/ B) convet 2. Fischer's determination of the structure of sugars involved building them up by adding HCN to their aldehyde group. Draw the structures of the twoOm )H products which would be formed by this method from OH the saccharide on the right. Pro duets 3. Fischer then converted the -CE N group to an aldehyde (-C-Hto yield a new carbohydrate.. What type of reaction or reactions would be required to convert the nitrile to an aldehyde? a. hydrolysis c. hydrolysis and oxidation b. hydrolysis and reduction d. hydrolysis and keto-enol tautomerism 4. The structure on the right would be named_ a. D-threose c. D-erythrose b. L-threose d. L-erythrose 5. In the space on the right draw the structure of the disaccharide a-D-galactopyranosyl (1-4)a-D-galactopyranose

Answer 1

애 애 hene ral or ( CH20 hag It is hex overall +is Adaohexos e : fes Its and it n otete te lane PPL

Yap, Compound would be 야 tically henta it will be opticauy achve