ジャドマイシン類の合成研究

抄録

Jadomycins A and B are unique 8<i >H-benzo[b]oxazolo[3,2-f]phenanthridine polyketide antibiotics containing isoleucine unit in the 1,3-oxazolidin-5-one ring, isolated from Streptomyces venezuelae. It has been reported that jadomycin B and its analogs with other amino acid units show anti-MRSA, DNA cleaving and cytotoxic activities. Herein, we report the syntheses of jadomycin A and its analogs.
Suzuki-Miyaura coupling of benzoxaborole with bromojuglone gave 2-arylnaphthoquinone as a key intermediate. Introduction of L-isoleucine to this compound, Dess-Martin oxidation, and deprotection of the MOM group produced jadomycine A. Jadomycin M and W aglycons were also synthesized from the same intermediate. In trials for the synthesis of jadomycin S aglycon, reconstruction of an oxazolidine ring to oxazoline one was observed, allowing us to propose the possible structural revision of jadomycins S.