# Recent advances in Norrish–Yang cyclization and dicarbonyl photoredox reactions for natural product synthesis

## TL;DR

This review highlights recent progress in using Norrish–Yang cyclization and dicarbonyl photoredox reactions to synthesize complex natural products.

## Contribution

The paper provides a comprehensive overview of the latest applications and mechanisms of Norrish–Yang cyclization and quinone photoredox reactions in natural product synthesis.

## Key findings

- Norrish–Yang cyclization efficiently constructs sterically hindered ring structures from dicarbonyls.
- Quinone photoredox reactions enable stereoselective synthesis of structures like spiroketals via single-electron transfer.
- These reactions offer streamlined pathways for assembling complex natural product frameworks.

## Abstract

In recent years, the Norrish–Yang cyclization and related photoredox reactions of dicarbonyls have been extensively utilized in natural product synthesis. This review summarizes the latest advancements in these reactions for constructing terpenoids, alkaloids, and antibiotics. Through Norrish–Yang cyclization, dicarbonyls (e.g., 1,2-diketones and α-keto amides) can efficiently construct sterically hindered ring structures, which can further undergo ring-opening or rearrangement reaction to assemble complex molecular frameworks. Additionally, quinone photoredox reactions involving single-electron transfer (SET) processes provide novel strategies for the stereoselective synthesis of useful structures such as spiroketals. This review, drawing on examples from recently reported natural product syntheses, elaborates on reaction mechanisms, factors governing regioselectivity and stereoselectivity, and the impact of substrate structures on reaction pathways. These reactions not only serve as robust tools for the streamlined synthesis of natural products but also establish a solid foundation for subsequent pharmaceutical investigations.