Sixteen aldohexosea are possible. How many of these do not undergo mutarotation or osazone formation ?

Explanation

To solve the problem of how many of the 16 aldohexoses do not undergo mutarotation or osazone formation, we need to analyze the characteristics of aldohexoses.

### Step-by-Step Solution:

1. **Identify the Total Number of Aldohexoses**:
- Aldohexoses are six-carbon sugars with an aldehyde group. There are 16 possible aldohexoses, which include glucose, galactose, mannose, etc.

2. **Understanding Mutarotation**:
- Mutarotation is the change in optical rotation that occurs when an anomeric carbon (the carbon that was part of the carbonyl group in the open-chain form) is converted between its alpha and beta forms in solution.
- All aldohexoses have an anomeric carbon and can exist in both alpha and beta forms, hence they undergo mutarotation.

3. **Understanding Osazone Formation**:
- Osazone formation occurs when reducing sugars react with phenylhydrazine to form osazones.
- All aldohexoses are reducing sugars because they have an aldehyde group, which can be oxidized. Therefore, they will all react with phenylhydrazine and form osazones.

4. **Conclusion**:
- Since all 16 aldohexoses undergo both mutarotation and osazone formation, the number of aldohexoses that do not undergo these processes is **0**.

### Final Answer:
**0 aldohexoses do not undergo mutarotation or osazone formation.**