Pohmakotr, Manat; Boonkitpattarakul, Kanhokthron; Ieawsuwan, Winai; Jarussophon, Suwatchai; Duangdee, Nongnaphat; Tuchinda, Patoomratana; Reutrakul, Vichai Tetrahedron, 2006 , vol. 62, # 25 p. 5973 - 5985