# Dearomatization of Aromatic Carbonyl Compounds by Photocycloaddition Reactions to 1,1-Dimethylallene

## TL;DR

This paper explores a chemical reaction that adds a specific molecule to aromatic compounds, forming new structures with predictable patterns.

## Contribution

The study reveals a selective photocycloaddition method for dearomatizing aromatic carbonyl compounds.

## Key findings

- Photocycloaddition occurs exclusively at the benzene core of aromatic carbonyl compounds.
- Acetophenone derivatives yield para products in 50–58% yields.
- A reaction cascade from ortho addition in 2-methoxyacetophenone produces bicyclic products with 29–74% yields.

## Abstract

The photocycloaddition of 1,1-dimethylallene
to various
aromatic
carbonyl compounds was found to occur exclusively at the benzene core.
While the reaction with methyl 2-methoxybenzoate resulted in a mixture
of products resulting from ortho, meta, and para photocycloaddition, acetophenone and
its 4-substituted derivatives delivered the respective para photocycloaddition products in 50–58% yields. For 2-methoxyacetophenone,
an ortho photocycloaddition initiated a reaction
cascade, which led to bicyclic products by the incorporation of a
nucleophile in 29–74% yields.