Preparation and crystal structures of two 3-anthracenyl isoxazolyl sulfonamides

(Chemical Equation Presented) Lateral metalation and oxidation of 3-(9′-anthryl)-isoxazoles (1), using Davis' oxaziridine (6), produced the desired hydroxylation (2), along with sulfonamide adduct (3), and in the case of the use of butyl lithium as base, butyl addition products (4) and (5). Structures of isoxazole sulfonamides (3a) and (5a), were obtained as the SR/RS-diastereomer, however, studies indicate that this is a consequence of the crystallization process. Metalation studies with isoxazole (8) demonstrate that hydroxylation (9), can be carried out cleanly, minimizing formation of (10), using camphorsulfonyloxaziridine (7) as an electrophile.