Synthesis of saframycins. X. Transformation of (-)-saframycin A to (-)-saframycin Mx type compound with the structure proposed for saframycin E.
Treatment of (-)-saframycin A (1a) with selenium oxide in acetic acid afforded (-)-saframycin G (1g), and a catalytic reduction and regioselective oxidation sequence afforded the saframycin Mx type compound (3). We applied this methodology to the transformation of (+/-)-5-hydroxysaframycin B (11) to the hydroquinone (1e). Acetylation of 1e with acetic anhydride in pyridine gave the triacetate (13), which is identical with the triacetyl derivative of natural saframycin E.
Saito
N
N
Meiji College of Pharmacy, Tokyo, Japan.
Harada
S
S
Nishida
M
M
Inouye
I
I
Kubo
A
A
D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000737:chemistry; D000903:Antibiotics, Antineoplastic / Q000138:chemical synthesis* / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D007546:Isoquinolines / Q000138:chemical synthesis / Q000737:chemistry; D010084:Oxidation-Reduction; D013237:Stereoisomerism
D000900:Anti-Bacterial Agents; D000903:Antibiotics, Antineoplastic; D007546:Isoquinolines; C096067:saframycin E; C026925:saframycin A