Selective synthesis of the para-quinone region of geldanamycin

[GRAPHICS] The quinone portion of the ansamycin geldanamycin was made with complete selectivity from the 1,4-hydroquinone generated from a 1,4-bis-methoxymethyl (MOM) ether intermediate. Palladium catalysis with air gave the desired product in 98% isolated yield. The structure was established using NMR, UV, and X-ray analysis with comparisons to geldanamycin, ortho-quino-geldanamycin and a model compound.