Methyl 6α-ethoxyformamido-6β-phenoxyacetamidopenicillanate

Cameron, A. F.; McElhatton, J.; Campbell, Malcolm M.; Johnson, Gerald A.

doi:10.1107/s0567740879006130

Cited by 5 publications

(3 citation statements)

References 7 publications

(7 reference statements)

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“…In general, the amide bond geometry of structurally characterized β-lactams presented in Figures and − can be characterized as N-pyramidalized (average χ N of 54.4°), while twist is less significant (average τ of 19.2°), as expected from the geometry of the fused four-membered ring system. There is only a very scattered correlation between N-pyramidalization and twist of the amide bond, with the general trend of higher twist with increased nitrogen pyramidalization ( R 2 = 0.30).…”

Section: Cyclic Amides: N-pyramidalization 40–60°mentioning

confidence: 86%

“…The most common are [ 2 .4.0] and [ 2 .3.0] ring systems with the six-membered ring such as 1,3-oxazinane (e.g., 4.30 ), and more common five-membered ring, such as thiazolidine 1,1-dioxide (e.g., 4.32 ), thiazolidine 1-oxide (e.g., 4.33 ), thiazolidine (e.g., 4.34 ), 1,3-selenazolidine (e.g., 4.36 ), pyrrolidine (e.g., 4.81 ), imidazolidine (e.g., 4.94 ), or oxazolidine (e.g., 4.101 ) . In general, more dense substitution of the fused ring, in particular at the α-positions to the nitrogen atom and the carbonyl group and ring unsaturation, result in higher N-pyramidalization. − These N-pyramidalized amides are well-known to be highly reactive as acylating reagents and are important pharmacophores in medicinal chemistry research.…”

Section: Cyclic Amides: N-pyramidalization 40–60°mentioning

confidence: 99%

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Acyclic Twisted Amides

2021

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In this contribution, we provide a comprehensive overview of acyclic twisted amides, covering the literature since 1993 (the year of the first recognized report on acyclic twisted amides) through June 2020. The review focuses on classes of acyclic twisted amides and their key structural properties, such as amide bond twist and nitrogen pyramidalization, which are primarily responsible for disrupting n N to π* CO conjugation. Through discussing acyclic twisted amides in comparison with the classic bridged lactams and conformationally restricted cyclic fused amides, the reader is provided with an overview of amidic distortion that results in novel conformational features of acyclic amides that can be exploited in various fields of chemistry ranging from organic synthesis and polymers to biochemistry and structural chemistry and the current position of acyclic twisted amides in modern chemistry.

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Section: Cyclic Amides: N-pyramidalization 40–60°mentioning

confidence: 86%

Section: Cyclic Amides: N-pyramidalization 40–60°mentioning

confidence: 99%

Acyclic Twisted Amides

2021

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“…CH" C : CH 2 (methylallene) than to the mean value of 1.335 (5) ,& of a simple ~-c,_c,/t,.,_,_,~ double bond (Sutton, 1965). The O-C(=O)-NH chain linking rings B and D has a geometry similar to the corresponding chain in C20H25NaOTS (Cameron, McElhatton, Campbell & Johnson, 1979) where the ratios A/(o~ + o2) 1/2 are within 1.3 for the bond lengths and within 2.2 for the 7-METHYL-3- METHYLENETRICYCLO[5.3.0 angles. The overall X 2 = ~ (A/o) 2 for the three bond lengths and three angles is only 12.5.…”

Section: Ch2 (I)mentioning

confidence: 87%

7-Methyl-3-methylenetricyclo[5.3.0.01,4]dec-5-yl phenylcarbamate

Ahmed¹,

Przybylska²

1980

Acta Crystallogr Sect B

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1‐Cyanalkyliden‐substituierte 1,3‐Dithietanone als Cyanthioketen‐Äquivalente. Umsetzung zu 1,3,5‐Dithiazin‐4‐onen und 2‐Azetidinthionen

Schaumann¹,

Wriede²,

Adiwidjaja³

1984

Chem. Ber.

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Die Thiolyse der 3,3-Dichloracrylonitrile 1 fuhrt zu Dithiolaten 3, die sich zu Keten-dithioacetalen 5 alkylieren oder mit Phosgen zu den Titelverbindungen 8 acylieren lassen. Das uber die 1-Cyanoalkylidene-substituted 1 ,IDithietanones as Cyanothioketene Equivalents. Conversion into 1,3,5-Dithiazin-4-ones and 2-Azetidinethiones Thiolation of 3,3-dichloroacrylonitriles 1 leads to dithiolates 3, which can be alkylated to give ketene dithioacetals 5 or acylated with phosgene to yield the title compounds 8. rert-Butyl(cyan0)-thioketene (912) formed via 12 + 21 cycloreversion of 8c was found to be highly unstable. However, dithietanone 8c can be used directly as thioketene equivalent in the reaction with dimethylamine or aminoazirines 28 to give thioamides 12b, 33,34, and the 3-thiazoline 30. On addition of azomethines 17 or 2-thiazolines 24 to 8c, 1,3,5-dithiazin-4-one derivatives 19 or 25 are formed via nucleophilic attack at C-2 of the four-membered ring. The constitution of 19e was proven by an X-ray structural investigation. In the presence of an electron-rich 6-aryl residue, heterocycles 19 easily eliminate carbon oxide sulfide to give the azetidinethiones 21d -f , h, which can be considered as [2 + 21 cycloadducts of thioketene 9 c with azomethines. On heating, 8c and the 2-thiazoline 24b react to give bicyclic 27, whose constitution could be derived from an X-ray study.Seit Cyanketene durch Thermolyse von 2,S-Diazido-I ,4-benzochinonen bequem zuganglich sind, zahlt vor allem tert-Butylcyanketen zu den am haufigsten benutzten Ketenen'). Versuche, das zum Vergleich interessierende tert-Butyl(cyan)thio keten (9c) durch Blitzthermolyse von 4-terr-Butyl-l,2,3-thiadiazol-5-carbonitri12) oder durch 0 Verlag

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Methyl 6α-ethoxyformamido-6β-phenoxyacetamidopenicillanate

Abstract: The absolute stereochemistry of (II), although not determined from the present analysis, is inferred from the known absolute stereochemistry at C(3) of the starting material (I).

Cited by 5 publications

References 7 publications

Acyclic Twisted Amides

Acyclic Twisted Amides

7-Methyl-3-methylenetricyclo[5.3.0.01,4]dec-5-yl phenylcarbamate

1‐Cyanalkyliden‐substituierte 1,3‐Dithietanone als Cyanthioketen‐Äquivalente. Umsetzung zu 1,3,5‐Dithiazin‐4‐onen und 2‐Azetidinthionen

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