Exploring Synthetic Pathways for 2-Acetyl-1-Pyrroline: Challenges and Prospects

ABSTRACT

This article presents a comprehensive review of the various synthetic pathways developed over the last four decades for the synthesis of 2-acetyl-1-pyrroline (2-AP), a compound known for its significant contribution to flavor of rice. These approaches can be categorized into four main types based on retrosynthetic analysis: oxidation of suitable precursors, Grignard reactions involving 1-pyrroline carboxylates, cyclization of 6-amino 2,3-hexanedione, and hydrolysis of the enol ether of 2-AP. While these methods have aimed to provide alternative routes to produce 2-AP, some of them exhibit clear limitations, including complex and time-consuming synthetic steps, the use of expensive or hazardous chemicals. Additionally, the well-known instability of 2-AP presents significant obstacles to the development of its synthesis. Therefore, there is a pressing requirement for the creation of a simple, effective, and feasible method for preparing 2-AP.

KEYWORDS:

• 2-Acetyl-1-pyrroline
• synthesis
• oxidation
• Grignard reaction
• 6-amino 2,3-hexanedione
• enol ether

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (No. 32130083).