Experimental
Formation of Chloroketone 41:
To ketalpyrrole 40 (30 mg, 0.047 mmol) in THF (2.0 mL) was added benzyltrimethylammonium dichloroiodate (54 mg, 0.155 mmol). The resulting orange solution was heated at 60 °C for 1.75 hours, then quenched with 5% aqueous Na2S2O4 (10 mL) and extracted with EtOAc (10 mL). In quenching this reaction it is important to use a large excess of Na2S2O4 and completely remove all color from the organic layer, as excess dichloroiodate and byproducts from the reaction are capable of decomposing the product upon concentration. The organic layer was washed with brine (10 mL), then dried with MgSO4 and evaporated to give pure chloroketone 41 as a white powder (28 mg, 97%). Note: when running this reaction on a large scale, it is useful (but not required) to pass the EtOAc layer of the extraction through a small plug of MgSO4 and silica before evaporation to remove trace impurities.
Safety Notes:
Sodium dithionite is flammable and liberates toxic gases on contact with acid, so it should be kept under the fume hood and away from flame at all times. Benzyltrimethylammonium dichloroiodate is a skin, eye, and respiratory irritant; reasonable precautions should be taken.
"Actually, I'm German Irish..."
Fun Fact: Tom Hagen was, no doubt, a pretty poor Consigliere, but it's not because he wasn't a Sicilian. In fact, the Don readily admits that the best Consigliere would be a chemist. Think about Genco Abbandando! Definitely a chemist in disguise...
Glossary of General Experimental Terms:
Glossary for Safety Terms:
1) Dithionite is a reducing agent, used here to quench the reaction by removing the oxidative function of dichloroiodate.
