A Study of Hydrogenolytic Desulfurization by Means of Hydrazine

摘要

Several thioketals were prepared incorporating many structural features and the hydrazine defulfuration of these was studied. An interesting tangential development which emanated during the investigations was that of the interaction of cyclo-propane rings with carbonyl functions. Using the steroid molecule to ensure a fixed and discernible stereochemistry, it was possible to establish the principle of conjugative interaction of the electrons of the cyclopropane ring and the pi-system of a carbonyl. Acid catalyzed ring opening of a cyclopropane conjugated with a carbonyl will involve that sigma-electron pair of the three membered ring potentially capable of early overlap with pi-orbital system of the carbonyl group. No other electronic or steric factors loom as important. (Extracted)