2‐Oxabicyclo[2.1.1]hexan und 2‐Oxabicyclo[2.1.1]hex‐5‐yl‐Derivate

Abstract

Fragmentation is enhanced by better leaving groups, elevated temperatures, and less nucleophilic solvents. Ring expansion, with formation of 2-oxanorbornyl cations, occurs to less than 1 %, if at all. Uns interessierte an dieser Verbindungsklasse vor allem die Umlagerung von 2-Oxabicyclo[2.1.1]-hex-5-ylmethyl-Derivaten (3) zu 2-Oxanorbornylkationen (4, 6). uber die analoge Ringerweiterung von Bicyclo[2.1 .l]hex-5-ylmethyl-Derivaten (CH2 statt 0 in 3) zu Norbornylkationen haben wir berichtet ", ebenso iiber die Erzeugung von 4 und 6 aus den Edukten 5 bzw. 78). Um die Konfiguration unserer Edukte vom Typ 3 abzusichern, haben wir auch die Stammverbindung 1 hergestellt.

A New Entry into 2-Azabicyclo[2.1.1]hexanes via 3-(Chloromethyl)cyclobutanone

“…Also characteristic is the large coupling constant of about 11 Hz between H a and H c due to the W-shape of the C-skeleton. This is also in agreement with similar coupling constants found in methanoproline ( 1 ) itself (14.7 Hz) 3a and in 2-oxabicyclo[2.1.1]hexane (10.8 Hz) 1 Coupling Constants of 2-Aza-2-isopropylbicyclo[2.1.1]hexane Hydrochloride ( 15 ) Obtained by 1 H-NMR Experiments (D 2 O) …”

Water‐Soluble Non‐Classical Benzene Mimetics

“…Inorganic bases (entries 1-4) worked generally better than the organic ones (entries 5-8). Both iodine and N-iodosuccinimide worked well (entries 13,14), but iodine gave better yields.…”

“…Therefore, we had to develop alternative methods. Although the non-substituted [13] or chain-substituted 2-oxabicyclo[2.1.1]hexanes [14] are well-documented, the bridgehead-substituted structures remain unknown in peer-reviewed literature. In 2017, however, in a patent, a reaction of alkene L-1 into product L-2 and the subsequent interesting transformations of functional groups was described (Scheme 2).…”

Water‐Soluble Non‐Classical Benzene Mimetics

“…Therefore, we had to develop alternative methods. Although the non‐substituted or chain‐substituted 2‐oxabicyclo[2.1.1]hexanes are well‐documented, the bridgehead‐substituted structures remain unknown in peer‐reviewed literature. In 2017, however, in a patent, a reaction of alkene L‐1 into product L‐2 and the subsequent interesting transformations of functional groups was described (Scheme ) .…”

“…Inorganic bases (entries 1-4) worked generally better than the organic ones (entries [5][6][7][8]. Both iodine and N-iodosuccinimide worked well (entries 13,14), but iodine gave better yields.…”