5. Answer the following questions regarding 2-ketohexoses: ()Determine the total number of possible non-natural 2-ketohexose stereoisomers....

 

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5. Answer the following questions regarding 2-ketohexoses: ()Determine the total number of possible non-natural 2-ketohexose stereoisomers. () Choose one of the 2-ketohexose stereoisomers from part (), and then draw the structure in both zig-zag and Fischer projection forms. (ii) Draw the a-furanose form of the 2-ketohexose chosen in part (). (iv) Draw the structures of the products resulting from the reaction of the 2-ketohexose chosen in part () with NaBH.. Determine whether each of these structures is either chiral or achiral, and explain why. Draw the structure 4 resulting from a biosynthetic sequence starting from nicotinic acid and the aliphatic building block derived from the amino acid lysine. The answer must include some step-wise biosynthetic detail to account for the formation of 4 from the given building blocks. -COOH nicotinic acid H₂N COOH lysine NH₂ steps 4 5. Answer the following questions regarding 2-ketohexoses: ()Determine the total number of possible non-natural 2-ketohexose stereoisomers. () Choose one of the 2-ketohexose stereoisomers from part (), and then draw the structure in both zig-zag and Fischer projection forms. (ii) Draw the a-furanose form of the 2-ketohexose chosen in part (). (iv) Draw the structures of the products resulting from the reaction of the 2-ketohexose chosen in part () with NaBH.. Determine whether each of these structures is either chiral or achiral, and explain why. Draw the structure 4 resulting from a biosynthetic sequence starting from nicotinic acid and the aliphatic building block derived from the amino acid lysine. The answer must include some step-wise biosynthetic detail to account for the formation of 4 from the given building blocks. -COOH nicotinic acid H₂N COOH lysine NH₂ steps 4