Koshida, Shuhei; Suda, Yasuo; Fukui, Yasuhiro; Ormsby, Julie; Sobel, Michael; Kusumoto, Shoichi Tetrahedron Letters, 1999, vol. 40, # 31 p. 5725 - 5728 doi: 10.1016/S0040-4039(99)01084-9