... b Spectroscopic Department, EGIS Pharmaceuticals, H-1475 Budapest, POB 100, Hungary. Received 4 March 1988, Available online 12 July 2005. Abstract. ... F. Fu¨lo¨p, G. Berna'th, I. Pelczer; Tetrahedron Letters, 27 (1986), p. 2517 and references cited therein. ...