Über eine neue allgemeine Synthese von 3,3‐disubstituierten 2,3,4,5‐Tetrahydro‐1H‐(benzo[b]1,4‐diazepin)‐2‐onen durch Ringerweiterung 3,3‐disubstituierter 1‐(o‐Aminophenyl)‐azetidin‐2‐one
Abstract:Es wird über eine intramolekulare Umamidierung berichtet, welche in guter Ausbeute von den viergliedrigen 3,3‐disubstituierten 1‐(o‐Aminophenyl)‐azetidin‐2‐onen (V) durch Ringerweiterung zu den siebengliedrigen 3,3‐disubstituierten 2,3,4,5‐Tetrahydro‐1H‐(benzo[b]1,4‐diazepin)‐2‐onen (VII) führt. Neben der Synthese wird über die chemischen und physikalisch‐chemischen Eigenschaften dieser neuen Verbindungen, über deren IR.‐ und NMR.‐Spektren sowie über einige ihrer Umsetzungen ausführlich berichtet. Der mutmassl… Show more
“…[61] (f) Ring-closure of benzyl-protected hydroxylamines with β-bromopropionyl chlorides to give β-lactams and subsequent hydrolysis. [62] (g) Reformatzky reaction of an appropriate benzotriazole derivative with a 2-bromoalkanoate. [63] (h) Dialkylation of Boc-protected methyl 3-aminopropanoate via a doubly lithiated species [5] [34] or one of the diastereoisomers is formed preferentially.…”
“…[61] (f) Ring-closure of benzyl-protected hydroxylamines with β-bromopropionyl chlorides to give β-lactams and subsequent hydrolysis. [62] (g) Reformatzky reaction of an appropriate benzotriazole derivative with a 2-bromoalkanoate. [63] (h) Dialkylation of Boc-protected methyl 3-aminopropanoate via a doubly lithiated species [5] [34] or one of the diastereoisomers is formed preferentially.…”
“…NtcoLAus et al 3) reported that the synthetic /3-lactam (1), for which the IR absorption (1715 cm-1) was also exceptional, was transformed to the seven-membered ring derivative (2) under acidic conditions (see Scheme 1). The structural relation between the /3-lactam and the free amino group of bleomycin is the same as in 1.…”
Section: Chemistry Of Bleomycin Xvii* Chemical Proof For the B -Lactmentioning
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