4-Hydroxybenzaldehyde → 4-Coumaric acid

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Reaction Steps

Sometimes it is convenient to derive the ether substituent from the hydroxyphenyl substituent at the same position the latter occupies, for example, in the following sequence of steps. Malonic acid and p-hydroxybenzaldehyde are reacted to form p-hydroxycinnamic acid, followed by esterification with methanol in the presence of conc H2SO4 to form the methyl ester. This ester is then reacted with TosMIC in the presence of NaH to form methyl 4-hydroxyphenylpyrrole-3-carboxylate ("P-carboxylate"). The P-carboxylate is then reduced with LiAlH4 in THF to the 3-methyl-4-hydroxyphenylpyrrole which is then reacted with allyloxybutyl bromide to yield the 4-(4-allyloxybutoxyphenyl-3-methyl-pyrrole.

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