Method for producing tetrahydropyranyl esters

Patent metadata

Field	Value
Publication number	US-10106517-B2
Application number	US-201615555723-A
Country	US
Kind code	B2
Filing date	Mar 4, 2016
Priority date	Mar 5, 2015
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

The present invention relates to a method for preparing tetrahydropyranyl esters from the corresponding 4-hydroxytetrahydropyran compounds by reaction with a ketene compound.

First claim

The invention claimed is:

1. A method for preparing tetrahydropyranyl esters of the general formula (I)

where
R 1 , R 2 , R 3 and R 4 are each independently hydrogen, straight-chain or branched C 1 -C 12 -alkyl, straight-chain or branched C 2 -C 12 -alkenyl, unsubstituted or C 1 -C 12 -alkyl- and/or C 1 -C 12 -alkoxy-substituted cycloalkyl having a total of 3 to 20 carbon atoms or unsubstituted or C 1 -C 12 -alkyl- and/or C 1 -C 12 -alkoxy-substituted aryl having a total of 6 to 20 carbon atoms,
R 5 is hydrogen or straight-chain or branched C 1 -C 12 -alkyl, and
R a and R b are each independently hydrogen or in each case unsubstituted or substituted C 1 -C 12 -alkyl, C 5 -C 8 -cycloalkyl or C 6 -C 14 -aryl,
in which at least one 4-hydroxytetrahydropyran compound of the general formula (II) is provided

where R 1 , R 2 , R 3 , R 4 and R 5 are as defined above, and the compound having the general formula (II) is subjected to a reaction with a ketene (III),
CR a R b ═C═O  (III)

where R a and R b are as defined above.

2. The method according to claim 1 , where R 1 is a straight-chain or branched C 1 -C 6 -alkyl, straight-chain or branched C 2 -C 6 -alkenyl or phenyl.

3. The method according to claim 1 , where R 1 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, n-hexyl or phenyl.

4. The method according to claim 1 , where R 1 is n-propyl or isobutyl.

5. The method according to claim 1 , where R 2 , R 3 and R 4 are all hydrogen.

6. The method according to claim 1 , where R 5 is methyl.

7. The method according to claim 1 , where R 5 is ethyl.

8. The method according to claim 1 , where R a and R b are both hydrogen.

9. The method according to claim 1 , wherein the compound of the general formula (II) is subjected to a reaction with a ketene (III) at a temperature in the range of 0 to 150° C.

10. The method according to claim 1 , wherein the compound of the general formula (II) is subjected to a reaction with a ketene (III) at a temperature in the range of 10 to 120° C.

11. The method according to claim 1 , wherein the compound of the general formula (II) is subjected to a reaction with a ketene (III) in the absence of an added catalyst.

12. The method according to claim 1 , wherein the compound of the general formula (II) is subjected to a reaction with a ketene (III) in the presence of a catalyst.

13. The method according to claim 1 , wherein the compound of the general formula (II) is subjected to a reaction with a ketene (III) in the presence of a catalyst selected from zinc salts.

14. The method according to claim 1 , wherein the compound of the general formula (II) is subjected to a reaction with a ketene (III) in the presence of a catalyst selected from zinc salts of carboxylic acids.

15. The method according to claim 1 , wherein the compound of the general formula (II) is subjected to a reaction with a ketene (III) in the presence of a catalyst which is zinc acetate.

16. The method according to claim 12 , wherein the catalyst is used in an amount of 0.01 to 2% by weight based on the total amount of the compound (II).

17. The method according to claim 15 , wherein the catalyst is used in an amount of 0.02 to 0.5% by weight, based on the total amount of the compound (II).

18. A method for preparing 2-substituted 4-methyltetrahydropyranyl esters of the general formula (I.1)

where
R 1 is hydrogen, straight-chain or branched C 1 -C 12 -alkyl, straight-chain or branched C 2 -C 12 -alkenyl, unsubstituted or C 1 -C 12 -alkyl- and/or C 1 -C 12 -alkoxy-substituted cycloalkyl having a total of 3 to 20 carbon atoms or unsubstituted or C 1 -C 12 -alkyl- and/or C 1 -C 12 -alkoxy-substituted aryl having a total of 6 to 20 carbon atoms,
in which at least one 2-substituted 4-hydroxy-4-methyltetrahydropyran of the general formula (II.1) is provided

where R 1 is as defined above and the compound of the general formula (II.1) is subjected to a reaction with the ketene (III.1)
CH 2 ═C═O  (III.1).

19. The method according to claim 18 , wherein to provide the 2-substituted 4-hydroxy-4-methyltetrahydropyran of the general formula (II.1):
a) 3-methylbut-3-en-1-ol of the formula (IV)

is reacted with an aldehyde of the formula (V)
R 1 —CHO  (V)

where
R 1 is a straight-chain or branched C 1 -C 12 -alkyl, straight-chain or branched C 2 -C 12 -alkenyl, unsubstituted or C 1 -C 12 -alkyl- and/or C 1 -C 12 -alkoxy-substituted cycloalkyl having a total of 3 to 20 carbon atoms or unsubstituted or C 1 -C 12 -alkyl- and/or C 1 -C 12 -alkoxy-substituted aryl having a total of 6 to 20 carbon atoms,
in the presence of an acidic catalyst, wherein a reaction mixture is obtained comprising at least one 2-substituted 4-hydroxy-4-methyltetrahydropyran of the general formula (II.1), where R 1 is as defined above,
b) optionally the reaction mixture from step a) is subjected to a separation to obtain at least one fraction enriched in the 2-substituted 4-hydroxy-4-methyltetrahydropyrans of the general formula (II.1).

Assignees

• Basf Se
• Basf Se

Inventors

• Rüdenauer Stefan
• Stork Timon
• Pelzer Ralf
• Hickmann Volker
• Klos Margarethe

Classifications

• C07D309/12 Primary

  only hydrogen atoms and one oxygen atom directly attached to ring carbon atoms, e.g. tetrahydropyranyl ethers · CPC title

• C07D309/10 Primary

  Oxygen atoms · CPC title