Photooxygenation of enamines - a partial synthesis of progesterone

Chemical Modification of Tylosin.

“…Treatment of 6 with 1 equiv. ofNaBH4 afforded 20-homo relomycin (7) and pyridinium chlorochromate oxidation of the latter gave the desired 20-homo tylosin (8). The yield of the last two steps, 30% and 20% respectively, was unsatisfactory.…”

Theoretical studies of photo‐oxidative cleavage reactions of nitrogen‐activated CC double bonds of enamines, indoles, and tryptamines

“…Wasserman and Terao [6] similarly reported that enamines 18 ( m = 3-6) are cleanly cleavaged by photo-oxygenation to form two carbonyl fragments in methanol. Huber [7] Various experiments being presented are at least not inconsistent with our theoretically proposed zwitterionic mechanism [ 17,181 for photo-oxygenations of N-activated C-C double bonds in solution phase, which are involved in the compounds discussed above. N o effect of a radical inhibitor on the reaction of 10 strongly suggests the nonradical ionic (FN) [17] mechanism instead of singlet diradical and free radical (autooxidation) mechanisms.…”

“…Wasserman and Terao[6] similarly reported that enamines 18 ( m = 3-6) are cleanly cleavaged by photo-oxygenation to form two carbonyl fragments in methanol. Huber[7] also found the clean C-C cleavage reaction of enamine 15 [Rl = R3 = H, R2 = 22-morpholine] in methanol. On the other hand, Andoet al 181 examined the photo-oxygenation of similar enamine 16 [R1 = H , R2 = CH3, and R3 = 41 in pridine and found the C-C cleavaged and other oxidation compounds.…”

Corrigendum: Visible‐Light‐Mediated 1,2‐Acyl Migration: The Reaction of Secondary Enamino Ketones with Singlet Oxygen

“…In this Communication, the sentence starting in line 8 of the first text paragraph on page 12201 must be replaced by the following two sentences: “The reactions of singlet oxygen with enamines were firstly disclosed by Foote and Lin8a and Huber8b in 1968 (Scheme 1 a). And the similar double bond cleavage reaction of enaminones by singlet oxygen was reported by Wasserman and Ives [9] in 1976 (Scheme 1 b).” Scheme and Ref.…”