Photochemical transformations of small ring carbonyl compounds. XXX. Electron transfer in the photochemistry of azetidinyl ketones

Isomérisation thermique de vinyl-2 aziridines N-substituées

“…Ils sont, en eR'et, instables: si on les abandonne quelques jours A tempCrature ambiante, ils se transfonnent en deux nouveaux produits qui o11t pu Etre sCparCs. Le spectre de rmn de l'un d'eux est identiqi~e A celui dCcrit dans la IittCrature (9) (iv) Lorsque le systkme vinylique de l'aziridine porte un substituant en position 2, la pyrroline-2 peut prksenter les configurations cis et trans. Les rCsultats que nous avons observts inontrent que la stCrCosClectivitC de 1'isomCrisation des aziridines dtpend de la gComCtrie de leur double liaison (expkriences [8][9][10].…”

Involvement of azomethine ylides in the thermal rearrangement of aziridinyl ketones to pyrroles

“…This material was identical in all respects to an authentic sample of A-ierZ-butyl-3-phenylpyrrole (7). 33 Preparation and Thermolysis of cisand trans-N-tert-Butyl-2benzoyl-3-methylaziridine-T-metAyV-ds. A mixture containing 1.5 ml of l-phenyl-2-buten-l-one, 1.5 ml of deuterium oxide, a catalytic quantity of sodium deuteroxide, and 9 ml of dioxane was heated at 140°for 24 hr.…”

“…The solvent was removed under reduced pressure and the residue was recrystallized from ethanol to give 73 mg (71%) of A-zezZ-butyl-3-biphenylpyrrole: mp 95-97°; ir (KBr) 6.20, 6.40, 6.70, 7.30, 7.40, 8.03, 8.18, 8.65, 8.98, 9.13, 10.83, 11.98, 12.06, 12.83, 13.13, and 14.47 µ; uv (methanol) 298 nm (< 29,800); NMR (CDC13) 8 1.38 (s, 9 H), three triplets at 6.44 (1 H, J = 2.5 Hz), 6.75 (1 H, / = 2.5 Hz), and 7.08 (1 H, J = 2.5 Hz), and a multiplet centered at 7.45 (9 H); m/e 275 (M+), 260, 220, 219 (base), 217, 190, and 165. The structure of the pyrrole was further verified by comparison with an authentic sample. 33 Since the pure iraní-aziridine (12) was not available, a mixture enriched in this isomer (65% trans-35% cis) was heated in methanol at 165°for 30 min. The only product isolated (70%) was A-Zerí-butyl-3-biphenylpyrrole.…”

ChemInform Abstract: Synthesis of N‐Substituted Isothiazol‐3(2H)‐ones from N‐Substituted 3‐Benzoylpropionamides.

“…The white solid residue (5.5 g, 84%), mp 110-113°, proved to be almost pure amide 7a (pmr spectrum). Recrystallization from ethyl acetate-petroleum ether yielded a crystalline solid (72% yield), mp 116-117°, lit [8] mp 115-116°( after recrystallization from benzene-hexane); ir (nujol): 3425 (br, m), 1678 (sh, s), 1642 (sh, s) and 1555 (sh, s); pmr (deuteriochloroform): 1.33 (s, 9H, -CMe 3 ), 2.50 and 3.28 (two t, J=6 Hz, 4H, -CH 2 CH 2 -), 5.61 (br s, 1H, -NH-) and 7.26-8.00 (m, 5H, aromatic protons). The ir and pmr data agree with those already reported [8].…”

“…The only exception to this general method was noted for the reaction with tert-butylamine; in this case, the lactones 11 (Ar= -C 6 H 5 and -C 6 H 4 OCH 3 -4) were reported to isomerize to the corresponding 5-arylfuran-2(5H)-ones [4]. However, the isolation of the N-tert-butyl amide 7a (Scheme 3), from the reaction of the lactone 11 (Ar=-C 6 H 5 ) and tert-butylamine in refluxing acetonitrile, has been described [8].…”