Kabayashi, Susumu; Tokunoh, Ryosuke; Shibasaki, Masakatsu; Shinagawa, Rumi; Murakami-Murofushi, Kimiko Tetrahedron Letters, 1993, vol. 34, # 25 p. 4047 - 4050 doi: 10.1016/S0040-4039(00)60612-3