... Scheme 4 r 1 3c L 1 3s Page 3. HELVETICA CHIMICA ACTA - Vol. 69 ( I 986) 907 ... b) From 3c. A degassed soh. of 30 mg (2. REFERENCES [I] P. Margaretha, Tetrahedron Lert. 1971,4871. [2] E. Anklam, R. Ghaffari-Tabrizi, H. Hombrecher, S. Lau, P. Margaretha, Helu. Chim. ...