Synthesis and Structure of a New Semisynthetic Taraxerone Derivative Fused to a Pyrazine Ring through the C2-C3 Bond

A new semisynthetic derivative of natural taraxerone fused to a pyrazine ring through the C-2-C-3 bond, (4aR,6bR,14aR,16aS)-2,2,4a,6b,9,9,14a,16a-octamethyl-1,2,3,4,4a,5,6b,7,8,8a,9,14,14a,14b,15,16,16a,16boctadecahydrochryseno[1,2-g]quinoxaline, has been synthesized by the Willgerodt-Kindler reaction, and its structure was determined by X-ray analysis and NMR spectroscopy.