We present herein the base-induced isomerization of red uroleuconaphins A1 and B1 to yellow uroleuconaphins A2 and B2, respectively. Based on our preliminary results, we optimized the conversion conditions by...

We present herein a strong acid-promoted single-step transformation of red uroleuconaphin A1 into green viridaphin A2. Viridaphin A1 and bis-naphthoquinone were also obtained by performing the reaction in aqueous media....

A stereoselective synthesis of a pyranonaphthoquinone derivative found in aromatic polyketide-derived aphid pigments is reported herein. This approach features the anionic [4+2]-annulation of phthalides with a carbohydrate-derived optically active enone. Additional synthetic steps provide access to the monomer fragment of uroleuconaphins and viridaphins. The optimization for a facile preparation of phthalides bearing sulfonyl or cyano groups are also studied.

We present herein the chemical degradation of dimethyl uroleuconaphins A2 and B2 mediated by silica gel. The reaction promoted carbon–carbon bond cleavage of the dimeric structure, resulting in the monomeric...