Synthese und Konformation einiger Tetraoxaspirane

Synthesis and Qualitative Olfactory Evaluation of Benzodioxepine Analogues

“…Reaction of 2 with 1,3-dibromopropane in DMF at 1208 for 2 h gave 6 in a crude mixture containing dialkylated and monoalkylated catechol ether impurities as indicated by GC/MS analysis. An alternative procedure, with sodium and an etherified ethylene glycol as solvent, based on the protocol of Jamrozik and co-workers [8], provided similar yields. Microwave heating of 2 and 1,3-dibromopropane in DMF gave 6 in 55% yield as a clean mixture after 2 min at 200 W. Removal of brominated impurities was effectively achieved by precipitation with Et 3 N as the quaternary ammonium salts.…”

“…1 H-NMR (300 MHz, (CDCl 3 ): 6.92 -6.70 (m, HÀC (6), HÀC (8), HÀC(9)); 4.10 (t, J ¼ 5.3, CH 2 (2)); 4.08 (t, J ¼ 5.1, CH 2 (4)); 2.21 (s, arom. Me); 2.11 (quint., J ¼ 5.5, CH 2 (3)).…”

“…IR (neat): 2925w, 2867w, 1360w, 2342w, 1726w, 1613w, 1578w, 1504s, 1470w, 1444w, 1382w, 1304s, 1255m, 1230m, 1194w, 1153w, 1118w, 1085w, 1055w, 1006w. (8). Et 3 N (0.20 ml, 1.43 mmol) was added to a soln.…”