# Photochemistry of beta, gamma-unsaturated ketones

Is there a Norrish reaction for beta, gamma-unsaturated ketones? I know that Norrish reaction is used for saturated ketones, but in my homework I found this question. I have looked a lot in books and websites but I haven't found anything

Beta, gamma-unsaturated ketones can undergo Norrish photoreactions from the excited singlet state. For example, in the case (1) below $$\ce{R'}$$ would be an allyl radical if we had started with a beta, gamma-unsaturated ketone.