The structure and stereochemistry of the new Cu^Hg/? elemanolide, elemanschkuhriolide (8) from Schkuhria schkuhrioides is reported. Schkuhriolide (2), isolated from the same plant source, was transformed into 8 via a Cope rearrangement and this is the first [3,3] sigmatropic reaction of a melampolide with a lactone ring closed at C(8) and cis annelated. The biogenesis of C14a,H6/3 elemanolides from melampolides is discussed.
A convenient synthesis of derivatives of the pyrido[1′,2′:1,5]pyrazolo[3,4‐d]pyrimidine ring system from readily available 2‐amino‐3‐cyano‐5,7‐diphenylpyrazolo[1,5‐a]pyridine I and carbon disulfide, aryl isothiocyanates or nitriles is described. Derivatives of compound I undergo cyclization to the titled ring system by action of dimethylformamide dimethylacetal or hydrogen sulfide followed by treatment with triethylamine.
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