Sun, Dequn, Li Sun, Min Luo, and Zhaopin Gou. 2011. “One-Pot Preparation of 3-Hydroxymethyl 2,5-Diketopiperazine for Total Synthesis of Peticinnamin E”. Asian Journal of Chemistry 23 (11):5169-70. https://asianpubs.org/index.php/ajchem/article/view/11071.