This problem is meant to encourage you to think as a team about how you might establish the structure of a simple disaccharide, with some additional information at your disposal. Consider d-lactose (Section 24-11) and assume you do not know its structure. You are given the knowledge that it is a disaccharide, linked in a b manner to the anomeric carbon of only one of the sugars, and you are given the structures of all of the aldohexoses, as well as all of their possible methyl ethers. Deal with the following questions as a team or by dividing the work, before joint discussion, as appropriate. 

(a) Mild acid hydrolyzes your “unknown” to d-galactose and d-glucose. How much information can you derive from that result? 

(b) Propose an experiment that tells you that the two sugars are not connected through their respective anomeric centers. 

(c) Propose an experiment that tells you which one of the two sugars contains an acetal group used to bind the other. 

(d) Making use of the knowledge of the structure of all possible methyl ethers of the component monosaccharides, design experiments that will tell you which (nonanomeric) hydroxy group is responsible for the disaccharide linkage. 

(e) Similarly, can you use this approach to distinguish between a furanose and pyranose structure for the component of the disaccharide that can mutarotate? 

Table 24-1