Tetrahedron Letters, Vol32, No 6, pp 761-762.1991 I'mted III Great Brmun ... 1 -J I3 JONES, Tetrahedron, a, 3351, (1986) 2 - AM KLIBANOV, Act Chem Research, a, 114 (1990) 3 - A 2 ... and ref cited 5 - P HEIDUSCHKA, J DITTRICH, A BARTH, Pharmazle, a, 164 (1990) 6 - JB WEST ...