Synthetic studies on the azinothricin family of antitumour antibiotics. 5. Asymmetric synthesis of two activated esters for the northern sector of A83586C

Article abstract of DOI:10.1016/0040-4039(96)00804-0

An asymmeric synthesis of the activated esters 20 and 21 is reported. Both molecules equate with the C(28)-C(47) region of A83586C, and contain functionality appropriate for future unification with the hexapeptide unit. A useful new reaction is described for converting a methyl ester directly into a thioethyl or HOBT ester that operates under very mild conditions.