Simpson, Thomas J.; Smith, Robert W.; Westaway, Susan M.; Willis, Christine L.; Buss, Antony D.; Cannell, Richard J. P.; Dawson, Michael J.; Rudd, Brian A. M. Tetrahedron Letters, 1997, vol. 38, # 30 p. 5367 - 5370 doi: 10.1016/S0040-4039(97)01174-X