2G9X:
reference: Searching for Cyclin-Dependent Kinase Inhibitors Using a New Variant of the Cope Elimination., Griffin RJ, Henderson A, Curtin NJ, Echalier A, Endicott JA, Hardcastle IR, Newell DR, Noble ME, Wang LZ, Golding BT, J Am Chem Soc. 2006 May 10;128(18):6012-6013. PMID: 16669651

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