Synthesen von cis‐ und trans‐1,2,3,4,4a, 10a‐Hexahydro‐1,4‐benzodioxino[2,3‐c]‐pyridinen

Abstract

Cisand trans-l,2,3,4,4a, 10a-hexahydro-1,4-benzodioxino[2,3-c]pyridines have been synthetised and their structures established by NMR.-spectroscopy. Die kurzlich durch Coulson & Wooidridge [l] veroffentlichte Synthese des 1,2,3,4,4 a, 10a-Hexahydro-l,4-benzodioxino[2, 3-c]pyridins2) 1, eines bisher in der Literatur noch nicht beschriebenen Ringsystems, veranlasst uns, iiber einige Arbeiten auf diesem Gebiet zu berichten.

1,4-Benzodioxanes. I. Synthesis involving the reaction of .alpha.-halo Michael acceptors with catechol

“…Furthermore, direct reaction of catechol with 21a gave good yields of 20. Similarly, the isomeric ester 22 (not the expected 13) was obtained when catechol was treated with ethyl 2-bromo-3-methyl-2-butenoate in the presence of K2CO3 and KI (thus, the reported preparation of 13 via the reaction of catechol with ethyl ,/3-dibromovalerate by Augstein, et al,4 is no doubt in error).…”

A reinvestigation of the synthesis of cis-1,2,3,4,4a,10a-hexahydro[1,4]benzodioxino[2,3-c]pyridine and a synthesis of meso-2,3,4,5,5a,11a-hexahydro-1H-[1,4]benzodioxino[2,3-d]azepine

“…The cis-hexahydro-4,5-dihydroxy-l-methylsulfonylazepine 11 crystallized. It was collected, washed, and dried: mp 170-173 °C (45.1 g, 0.215 mol, 78%); NMR (Me2SO) 4.36 (exchangeable, 2), 3.74 (m, 2), 3.22 (t, 4), 2.82 (s, 3), 2.0-1.5 (m, 4); IR (Nujol) 3360-3280 (s), 1130 (s), 958 (s), 868 (s), 708 (m) cm"1; TLC (CHC13/CH30H 9:1 on silica gel GF) Rf 0.40.…”

“…Recrystallization from ethanol gave an analytical sample: mp 157-9 °C; NMR 6.84 (s, 4), 4.40 (m, 2), 3.86-3.00 (m, 4), 2.80 (s, 3), 2.50-1.60 (m, 4); IR (Nujol) 1594 (m), 1492 (s), 1314 (s), 1260 (s), 1138 (s), 1070 (s), 952 (m), 894 (m), 766 (s), 758 (s) cm-1; TLC-(CHC13 on silica gel GF) Rf 0.30.…”

Synthese und Eigenschaften von Spiro[1,3‐benzodioxol‐2,3′‐pyrrolidin]

“…1. Kondensation VOYL Brenzcatechin (1) mit 2,3-Dibrornbernsteinsaure-diathylester (2) oder Acetylendicarbonsaure-diathylester (5). Nach Cheng-Heng Kao et al [l] liefert die Kondensation des Dinatriumsalzes von 1 mit meso-oder rac-2 die entsprechenden Benzodioxan-dicarbonsaureester 3.…”