3,5-Dihydroxybenzaldehyde is suitable for use in the synthesis of 3,5-dihydroxyphenylglycine (3,5-DHPG). It may be used in the synthesis of: fulgide7 3,5-bis(undeca-4,6-diynyloxy)benzaldehyde 3,5-didodecyloxybenzaldehyde 1′-methyl-1′,5′-dihydro-2′-(3,5-bis(undeca-4,6-diynyloxy)phenyl)-1H-pyrrolo[3′,4′:1,9](C60-Ih)[5,6]fullerene (F2D) 3,5-Dihydroxybenzaldehyde is suitable for use in the synthesis of 3,5-dihydroxyphenylglycine (3,5-DHPG). It may be used in the synthesis of: fulgide7 3,5-bis(undeca-4,6-diynyloxy)benzaldehyde 3,5-didodecyloxybenzaldehyde 1′-methyl-1′,5′-dihydro-2′-(3,5-bis(undeca-4,6-diynyloxy)phenyl)-1H-pyrrolo[3′,4′:1,9](C60-Ih)[5,6]fullerene (F2D)