Alternative Way of Synthesizing DOPAL
The challenge thus far has been the synthesis of 3,4-dihydroxyphenylacetaldehyde (DOPAL). I have found a new way to possibly synthesize DOPAL by first making the 3,4-methylenedioxyphenylacetaldehyde intermediate by a method found in a paper titled "Some Derivatives of 2: 3-Dihydroxynaphthalene" Authors: Howell, FH and Taylor, DA. Journal of Chemical Society, Abstracts. 4252-4256 (1956).
Following this, we can synthesize DOPAL (using the intermediate synthesized above) by a method found in a paper titled "Synthesis of a Biochemically Important Aldehyde, 3,4-dihydroxyphenylacetaldehyde" Authors: Li, SW, Spaziano, VT et al. Journal of Bioorganic Chemistry, 24, 45-50 (1998). These methods are show below.
The only drawback to this method is the authors only had a 14% yield of DOPAL