Saturated heterocycless—35

Reactions of Levulinic Acid with Norbornane/ene Amino Acids and Diamines

“…[18,19] Kinetic measurements have revealed that di-endo compounds are more hindered -the retro-DielsϪAlder reaction of di-endo derivatives is known to be twice as fast as for di-exo compounds. [20] The present case focusses attention on the difference between the reactivities of these stereoisomeric norbornane/ene derivatives. No condensation of 1 in which the methyl group participates (as above) has been reported in the literature.…”

Structures of Saturated 5H‐Pyrrolo[1,2‐a][3,1]benzoxazin‐1(2H)‐ones Prepared from 4‐Oxopentanoic Acid and Cyclic Amino Alcohols

“…Preparation of the 3a-Methyloctahydro-(2 and 3) and -3,3a,5a,6,9,9a-hexahydro-5H-pyrrolo[1,2-a][3,1]benzoxazin-1(2H)-ones (4 and 5) and Di-endo (6 and 8) and Di-exo (7 and 9) 6,9-Methano Analogues: 4-Oxopentanoic acid (1, 1.2 g, 0.010 mol, Acros 12.514.01 levulinic acid, 98ϩ%), a cyclic or bicyclic amino alcohol [1.3 g of cis-or trans-2-(hydroxymethyl)cyclohexyl-1-amine, [39] or 1.3 g of cis-or trans-2-(hydroxymethyl)-4-cyclohexenyl-1-amine, [40] or 1.4 g of di-exo-or di-endo-3-aminobicyclo[2.2.1]hept-2-ylmethanol or 1.4 g of -hept-5-en-2-ylmethanol; [41,42] 0.010 mol], and PTSA (0.05 g) in toluene (50 mL) was heated under reflux for 2 h. After evaporation of the solvent, the residue was transferred to a chromatography column (alumina, Acros, activated, basic, 50Ϫ200 µ) and eluted with EtOAc. The physical data for compounds 2Ϫ9 are listed in Table 4.…”

Conformational analysis. XXVII—A 1H and 13C NMR conformational study of cis‐ and trans‐annelated 2‐p‐nitrophenyl‐4,5‐ and ‐5,6‐tetramethyleneper‐hydro‐ and 2‐p‐chlorophenyl‐4,5‐ and ‐5,6‐tetramethylenedihydro‐1,3‐oxazines

“…All 'H NMR spectra and the noise-decoupled l3C NMR spectra were recorded on a Jeol GX-400 FT-NMR spectrometer in CDCl, (3)(4)(5) except for the 'H NMR spectra of 10 and 11, which were recorded in CC14 on a Varian HA-100 NMR spectrometer and analysed with a LAOCOON 111 program. The AM= subspectra of 2-4 and 6-8 and the whole spectrum of 9 were completely first-order.…”