Processes for the manufacture of lactones

1. A process for the manufacture of a lactone, comprising:

(i) passing a feedstream comprising a reactive hydroxy acid having from about 4 to 10 carbon atoms per molecule in a vapor phase to a reaction zone containing a catalyst at conditions effective to convert the hydroxy acid to its corresponding lactone and water;

(ii) withdrawing from the reaction zone a product stream comprising the lactone and water characterized in that the feedstream comprising an effective amount of water vapor to enhance the conversion.

2. The process of claim 1 wherein the feedstream comprises from about 20 to 90 weight percent water vapor based on the total weight of water vapor and hydroxy acid.

3. The process of claim 2 wherein the feedstream comprising from about 50 to 90 weight percent water vapor based on the total weight of water vapor and hydroxy acid.

4. The process of claim 1 wherein the catalyst is a heterogeneous oxide catalyst.

5. The process of claim 4 wherein the catalyst comprises silica, alumina, or mixtures thereof.

6. The process of claim 4 wherein the catalyst comprises a Group I metal oxide or a Group II metal oxide or mixtures thereof.

7. The process of claim 1 further comprising removing at least a portion of the water from the product stream and recycling the water to the reaction zone.

8. The process of claim 1 wherein the hydroxy acid is selected from the group consisting of 5-hydroxy valeric acid, 5 hydroxy 4-methyl valeric acid, 5-hydroxy 2-methyl valeric acid, and 6-hydroxycaproic acid and mixtures thereof.

9. The process of claim 1 wherein the lactone is selected from the group consisting of delta-valerolactone, delta-caprolactone, ε-caprolactone, and mixtures thereof.

10. The process of claim 1 wherein the hydroxy acid is 6-hydroxycaproic acid and the lactone is ε-caprolactone.