Scheme 1. One-Step Synthesis of α, α-Dichloro-Retinal Analog.
Retinoic acid ethyl ester was reacted with dichloromethyllithium generated in situ from dichloromethane (DCM) and lithium diisopropylamide (LDA) in ethyl ether (Et2O) to generate α,α-dichloro-all-trans-retinone (DAR). 4 – 10% of DAR was produced in each reaction.
