An Improved Synthesis of 1,4‐Benzo‐ and 1,4‐Naphthoquinones Bearing Active Substituents

The synthesis of 1,4‐benzoquinones and 1,4‐naphthoquinones 3a–j carrying substituents such as methoxyl, ally or oxiranyl was substantially improved. The 1‐methoxy‐4‐methoxy‐methyloxy 2a–d, g–k or 1,4‐bis(methoxymethyloxy) derivatives 2e‐f were used, as a substrates instead of 1,4‐dimethoxy derivatives 1a–j hitherto used and they were oxidized with silver(II) dipicolinate. Among numerous examples, the synthesis a of new analog of ubiquinone 3d with the oxiranyl substituent, being a new bioactivated alkylating agent, is reported.