α‐Lactame (Aziridinone)

Abstract

a-Lactame wurden seit vielen Jahren als Zwischenstufen bei zahlri~ichen Prozessen nngenornrnen. Die Isolierung des ersten a-Lactams, dcs N-tert.-Birtyl-3-plti~it~I-aziridinot1s, gelang 1962. Inz wischen wurden weitere (stets Nund C-3-sub.stitirii~rti~) a-Lactanie darkvstellt. Die nieisten dieser sehr reaktiven Verbindungen unterliegcii leicht clcr thcrrnischm Zcmetzung ; airfallend ist die relative Bcstandigkeit des I ,3-Di-tert.-butylaziridinons, das erst bei 140 "C zu zerfallen beginnt. Nucleophile Reagentieri 5flnen den a-Lactamring. -It11 letzten Abschnitt werden einige Beziehirngen zivischen Stabilitat wid Substifirenten der a-Lactame abgelritrt, und es wird eine acvclische, planare oder f i s t planare Zwischenstufe niit delokalisierter Ladung zur Erkliirung drr beobaclttt~ten Effekte vorgeschlagert.

About 1‐triphenylmethyl‐3‐tert‐butylaziridinone and some of its reactions

“…The reaction yielded (Scheme 9), as expected [2,3], the corresponding methyl ester, methyl 2-triphenylmethylamino-3,3-dimethylbutanoate (9) as the major product, in 93% yield, mp 108-109 °C, accompanied by 7% of the α-methoxyamide, N-triphenylmethyl-2-methoxy-3,3-dimethylbutanamide (7). The physical and spectral properties of product 7 were identical with those of the methanolysis product.…”

“…It has been learned early [2,3] We chose to perform two reactions on 4 with protic nonionic nucleophiles: with methanol (Scheme 4) and with benzylamine (Scheme 5). When α-lactam 4 was refluxed in methanol (bp 65 °C) for 3.7 hours, N-triphenylmethyl-2methoxy-3,3-dimethylbutanamide (7) was formed in 86% yield, mp 100-101 °C (lit.…”

“…The stability of α-lactams (aziridinones) has been shown [2] to be dependent on the substituents at the 1 and 3 positions. To date, all stable pure α-lactams have a tertiary alkyl group attached to the nitrogen (e.g., tert-butyl or 1adamantyl).…”

Transition‐Metal‐Free Synthesis of N‐Hydroxy Oxindoles by an Aza‐Nazarov‐Type Reaction Involving Azaoxyallyl Cations

“…[16] In 1993,t he groupo f Kikugawas howede videncef or azaoxyallylc ationi ntermediates, [17] butthere hadnot been much progress untilJeffrey and co-workers reported thef irst practical[ 4 + +3] cycloaddition involvingazaoxyallyl cations. [16] In 1993,t he groupo f Kikugawas howede videncef or azaoxyallylc ationi ntermediates, [17] butthere hadnot been much progress untilJeffrey and co-workers reported thef irst practical[ 4 + +3] cycloaddition involvingazaoxyallyl cations.…”

Synthese und Photolyse von 1,4‐Dialkyl‐1,4‐dihydro‐5 H ‐tetrazol‐5‐onen und ‐thionen: Neue Wege zu Diaziridinonen und Carbodiimiden 1)

“…C 52.15 H 8.75 N 30.41 Gef. C 52.42 H 8.60 N 30.24 87 (82, M -C4H7 -C,Hd, 84 (13), 70 (7), 57 (100). (3.4 rnol) Natriumazid in 300 ml Wasser und 30 ml Ethanol tropfte man unter Riihren in 2.5h eine Ldsung von 248 g (3.4 C6HI2N4S (172.3) Ber.…”