摘要:
Isagarin (1) was synthesized in four steps from 1,4-dimethoxynaphthaldehyde (4). The key intermediate 2-(1,2-dihydroxyethyl)-1,4-naphthoquinon (3) was found to react with acylated pyridinium ylides to afford, after spontaneous intramolecular condensation, the desired natural product isagarin (1). Depending on the type of acylated pyridinium ylides, different types of new pyranonaphthoquinone derivatives were obtained.