34 α-Oxo-methylene類の新酸化反応-その生物活性天然物ならびにモデル化合物合成への応用

抄録

We have exploited the reactions utilizing "Soft-Soft specific affinity" between the divalent sulfur atom and the soft acid metal salts, e.g. thallium trinitrate (TTN) and mercuric perchlorate (MPC), as well as oxidation potential of the trivalent thallium atom. Now, the general synthetic methods using these reactions for the biologically active synthons (e.g. α-diketones, diosphenols, α-oxodimethylketals, α-keto acids, α-dimethoxy-γ-butyrolactones, etc.) have been established. The outline is shown in the text as Methods A and B. These procedures were shown to be very useful for synthesis of the family of the biologically active natural products. Thus, flavonols, steroidal derivatives, parent keto acid equivalents of the essential amino acids, and the synthetic intermediates for antibiotics (avenaciolide and sarcomycin) were successfully synthesized via a rapid key reaction under mild conditions. A new finding of methyl 2-nitrophenyl disulfide (21) as a unique bissulfenating reagent is noteworthy.