Gaj, Xinjie; Grigg, Ronald; Khamnaen, Tossapol; Rajviroongit, Shuleewan; Sridharan, Visuvanathar; Zhang, Lixin; Collard, Simon; Keep, Ann
Tetrahedron Letters, 2003 , vol. 44, # 40 p. 7441 - 7444

US4695572 A1, ;