The aromatic ketone 2,2',4,4'-tetramethoxybenzophenone hasa strong absorption band between 300 and 375 nm, and its
![](/images/gifchars/pi.gif)
,
![](/images/gifchars/pi.gif)
* triplet excited-state is selectively populated in methanol.Both facts make this aromatic ketone a versatile and efficienttriplet photocatalyst for the transformation of
![](/images/gifchars/alpha.gif)
-diazo carbonyl compounds into mainly the cyclopropanation product.