2-Pentenoic acid, 4-methyl-, ethyl ester → Ethyl (2E)-4-methyl-2-pentenoate

HRID 342907Notes

Reaction equation

HRID 342907 reaction equation
[CH3:1][C:2](=[CH2:10])[CH2:3][CH2:4][C:5]([O:7][CH2:8][CH3:9])=[O:6].CC(C)=CCC(OCC)=O.CC(C)C=CC(OCC)=O>>[CH3:1][CH:2]([CH3:10])/[CH:3]=[CH:4]/[C:5]([O:7][CH2:8][CH3:9])=[O:6]

Participants

4

Reactant 3

HCID 5662332-Pentenoic acid, 4-methyl-, ethyl esterHCID 30145233-Pentenoic acid, 4-methyl-, ethyl esterHCID 3416433Ethyl 4-methyl-4-pentenoate

Product 1

HCID 5315066Ethyl (2E)-4-methyl-2-pentenoateYield 90%

Procedure

On the other hand, the isomerization of ethyl 4-methyl-4-pentenoate to ethyl tratis-4-methyl-2-pentenoate is not favored thermodynamically. In fact the equilibrium distribution of isomers at 25° C. is as follows: ethyl 4-methyl-3-pentenoate (90%) and ethyl 4-methyl-2-pentenoate (10%). Despite this adverse equilibrium, ethyl 4- methyl-trans-2-pentenoate is obtained in 90% yield using the process of the present invention. The isomerization of ethyl 4-methyl-4-pentenoate also shows that this method accommodates the isomerization of olefin-esters that contain a tertiary carbon.

Workup

  1. customat 25° C.

Sources & evidence

ORD record
ord-71a351736a0348eb8442aa7d42da8f29
Source dataset
uspto-grants-1999_01
Patent number
US05859268

Reaction notes

Loading…