1. cf. E. Schenker and H. Herbst, in E. Jucker, “Progress in Drug Research,” V, p. 286 ff (1963).
2. Syntheses in the Colchicine Field
3. The Protection of Hydroxyl Groups
4. L. H. Piette, K. O. Loeffler, D. E. Green and G. A. Burlow, Privileged communication from NIMH.