An aldose is converted into its next higher homologue by :

Options

A. Ruff's method
B. Amadori rearrangement
C. Killiani synthesis
D. Wohl' method

Explanation

To convert an aldose into its next higher homologue, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Aldoses**:
- Aldoses are a type of monosaccharide that contain an aldehyde group (-CHO). They have the general formula Cn(H2O)n, where 'n' is the number of carbon atoms.

2. **Reaction Overview**:
- The conversion of an aldose to its next higher homologue involves the addition of a carbon atom. This can be achieved through a specific reaction known as the Killarney-Fisher synthesis.

3. **Addition of HCN**:
- In the Killarney-Fisher synthesis, the aldose reacts with hydrogen cyanide (HCN). This reaction introduces a new carbon atom into the structure.
- The reaction can be represented as:
\[ \text{Aldose} + \text{HCN} \rightarrow \text{CN} + 1 \text{ aldonic acid} \]

4. **Formation of Aldonic Acid**:
- The product of this reaction is a new compound known as an aldonic acid, which has one more carbon atom than the original aldose.

5. **Lactonization and Reduction**:
- The next steps involve lactonization (the formation of a lactone) and reduction (the addition of hydrogen).
- These steps lead to the formation of two different products, both of which are Cn+1 aldoses (the next higher homologues).

6. **Final Products**:
- The final products will be two C2 epimers (isomers differing in configuration at one specific carbon atom) of the aldose, which can be represented structurally.

7. **Conclusion**:
- The overall process of converting an aldose into its next higher homologue through the addition of HCN and subsequent reactions is known as the Killarney-Fisher synthesis.

### Final Answer:
An aldose is converted into its next higher homologue by the Killarney-Fisher synthesis.

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