CH 110K Lecture Notes - Lecture 9: Lithium Aluminium Hydride, Aldol Reaction, Boron
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No one solvent that fits all solvent rules: sometimes the ratio is unknown, it"s dependent upon purity of the substance, how we"ll do it. Add crude to 1 ml of methanol. Bring to a boil in a test tube. Add distilled water dropwise until just cloudy! Make distilled water the water bath so that they are the same temperature. Just a little bit has precipated out of solution. But don"t worry about, just don"t do it because it takes some dexterity. Take test tube out of the product: isolate, do melting point, % yield, and ir. Looking for disappearance of the carbonyl peak (3600 area) fluorine is still there. Solid hydrogen bonding is weaker than liquid hydrogen bonding so the oh peak will be small. Great yield is 60% 40-50 is good. Aldol reaction: if you have a carbonyl compound like acid aldehyde, the alpha proton to that carbonyl compound has a pka between 18 and 20.
