A racemic mixture of MPHPV was synthesized by dissolving erythro-GGE into ethyl acetate (Fisher) and then slowly adding 1.25 molar eq of DDQ and stirring for 30 min. The reaction was washed three times with saturated NaHCO3 to remove DDQH2 formed during the reaction. The MPHPV was purified via flash chromatography using hexane/ethyl acetate (0.33:0.67, v/v), as described previously (15 (link)), and then crystallized from the eluent via solvent evaporation.
HPV was synthesized as described previously for synthesis of β-deoxy-α-veratrylglycerone, except using 4-O-benzyl-acetovanillone as starting material, rather than acetoveratrone (15 (link)). Synthesis of HPV required an additional debenzylation step that was unnecessary in the synthesis of β-deoxy-α-veratrylglycerone.