(2R)-2-Methylpent-4-enoic acid explained

(2R)-2-Methylpent-4-enoic acid is an organic acid with the chemical formula C₆H₁₀O₂. Other names for this molecule include (R)-2-methyl-4-pentenoic acid, (R)-(-)-2-methyl-4-pentenoic acid, and methylallylacetic acid.

Synthesis

(R)-2-Methylpent-4-enoic acid can be synthesized using a chiral auxiliary such an oxazolidinone derivative, popularized by David Evans. One route of synthesis consists of three steps:

1. acylation of the oxazolidinone using triethylamine as a base, and DMAP as an acyl carrier catalyst
2. addition of a pentene group via enolate addition using Sodium bis(trimethylsilyl)amide as a base and allyl iodide as the pentene donor
3. and cleavage of the oxazolidinone by LiOH solution in hydrogen peroxide.^[1] and sulfite to reduce the peroxide to the acid.

Uses

(R)-2-Methylpent-4-enoic acid can also be used in synthesis of other chiral compounds. For example, it has been used in the process of synthesizing the drug Sacubitril as a reagent for adding a chiral center to the molecule.^[2]

Notes and References

1. Green. Rachel. Merritt. Andrew T.. Bull. Steven D.. 2008. A cleavable linker strategy for optimising enolate alkylation reactions of a polymer-supported Evans' oxazolidin-2-one. Chem. Commun.. en. 4. 508–510. 10.1039/b713966g. 18188484. 1359-7345.
2. Web site: W O 2016/119574 A 1. PDF. Patentimages.storage.googleapis.com. 15 March 2022.