ChemInform Abstract: A One-Pot Three Carbon Decarboxylative Ring Expansion of Cyclic Secondary Amino Acids. X-Ray Crystal Structure of a Substituted 1-Azacycloocta-2,4-diene.

ChemInform ◽  
1988 ◽  
Vol 19 (7) ◽  
Author(s):  
H. ARDILL ◽  
R. GRIGG ◽  
V. SRIDHARAN ◽  
J. MALONE
Keyword(s):  
Crystal Structure ◽  
Amino Acids ◽  
Ring Expansion ◽  
One Pot ◽  
X Ray ◽  
Secondary Amino ◽  
Substituted 1

scholarly journals The Rosetta all-atom energy function for macromolecular modeling and design

2017 ◽  
Author(s):  
Rebecca F. Alford ◽  
Andrew Leaver-Fay ◽  
Jeliazko R. Jeliazkov ◽  
Matthew J. O'Meara ◽  
Frank P. DiMaio ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Amino Acids ◽  
Energy Function ◽  
Crystal Structure Data ◽  
Structural Data ◽  
X Ray ◽  
The Past ◽  
Biomolecular Modeling ◽  
Macromolecular Modeling ◽  
Atom Energy

AbstractOver the past decade, the Rosetta biomolecular modeling suite has informed diverse biological questions and engineering challenges ranging from interpretation of low-resolution structural data to design of nanomaterials, protein therapeutics, and vaccines. Central to Rosetta’s success is the energy function: amodel parameterized from small molecule and X-ray crystal structure data used to approximate the energy associated with each biomolecule conformation. This paper describes the mathematical models and physical concepts that underlie the latest Rosetta energy function, beta_nov15. Applying these concepts,we explain how to use Rosetta energies to identify and analyze the features of biomolecular models.Finally, we discuss the latest advances in the energy function that extend capabilities from soluble proteins to also include membrane proteins, peptides containing non-canonical amino acids, carbohydrates, nucleic acids, and other macromolecules.

A New Bis-Tröger's Base: Synthesis, Spectroscopy, Crystal Structure and Isomerization

2006 ◽  
Vol 71 (9) ◽  
pp. 1278-1302 ◽  
Author(s):  
Martin Valík ◽  
Pavel Matějka ◽  
Eberhardt Herdtweck ◽  
Vladimír Král ◽  
Bohumil Dolensky
Keyword(s):  
Crystal Structure ◽  
Spectroscopic Data ◽  
The Other ◽  
X Ray Diffraction ◽  
One Pot ◽  
Molecular Tweezers ◽  
X Ray ◽  
Troger's Base ◽  
Ir And Raman ◽  
C Nmr

A new bis-Tröger's base was prepared from a tetraamine precursor as a mixture of two diastereoisomers. One of the isomers has a chair-like geometry, and the other possesses a boat-like geometry, embodying molecular tweezers. A one-pot preparation of bis-TB isomers and their interconversion under acid conditions was also studied. Structures of both isomers were confirmed by single-crystal X-ray diffraction. Extensive spectroscopic data, including 1H and 13C NMR, IR and Raman spectra of the isomers, are given.

Synthesis and Crystal Structure Determination of Cyclosporin H

2000 ◽  
Vol 65 (8) ◽  
pp. 1317-1328 ◽  
Author(s):  
Alexandr Jegorov ◽  
Ladislav Cvak ◽  
Aleš Husek ◽  
Petr Šimek ◽  
Anna Heydová ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Amino Acids ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Acid Catalyzed ◽  
Products Of Reaction ◽  
Cyclosporin H

Acid-catalyzed degradation of cyclosporin A was studied in various solvents and products of reaction were monitored by HPLC. Identification of amino acids and their chirality were determined after hydrolysis and derivatization by GC-MS. Cyclosporin H was isolated as the principal product and its structure was determined by X-ray diffraction: Cyclosporin H- diethyl ether-water (1 : 0.5 : 1) crystallizes in the monoclinic space group I2 with a = 12.338(2) Å, b = 18.963(2) Å, c = 34.074(3) Å, β = 96.47(2)°, Z = 4, and V = 7 921.4(17) Å3.

Tetrahydropyridine (THP) ring expansion under the action of activated terminal alkynes. The first synthesis and X-ray crystal structure of tetrahydropyrimido[4,5-d]azocines

2006 ◽  
Vol 47 (6) ◽  
pp. 999-1001 ◽  
Author(s):  
Leonid G. Voskressensky ◽  
Tatiana N. Borisova ◽  
Innokenti S. Kostenev ◽  
Larisa N. Kulikova ◽  
Alexey V. Varlamov
Keyword(s):  
Crystal Structure ◽  
Ring Expansion ◽  
Terminal Alkynes ◽  
X Ray

Unexpected Pyrolytic Behaviour of Substituted Benzo[c]thiopyran and Thieno[2,3-c]thiopyran S,S-dioxides

2014 ◽  
Vol 67 (9) ◽  
pp. 1288 ◽  
Author(s):  
R. Alan Aitken ◽  
Clémence Hauduc ◽  
M. Selim Hossain ◽  
Emily McHale ◽  
Adrian L. Schwan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ring Expansion ◽  
Hydrogen Atom Transfer ◽  
Membered Ring ◽  
X Ray ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis ◽  
Higher Temperature ◽  
Intramolecular Hydrogen ◽  
Carbonyl Products

Flash vacuum pyrolysis (FVP) of benzo[c]thiopyran S,S-dioxide (1) results in formation of indene and 2-vinylbenzaldehyde as previously described. A range of eight analogues with various substitution patterns are found to behave differently. In general, there is no extrusion of SO2 to give products analogous to indene, but unsaturated carbonyl products analogous to 2-vinylbenzaldehyde are formed in most cases by way of ring expansion to a 7-membered ring sultine, extrusion of SO, and intramolecular hydrogen atom transfer. Other processes observed include formation of anthracene via an isomeric 7-membered sultine with loss of SO, CO and methane or butane, and formation of 4-ethylidene-4,5-dihydrocyclobuta[b]thiophenes by way of SO loss, a radical rearrangement, and extrusion of acetone. The analogues with a halogen substituent at position 8 on the benzene ring require a higher temperature to react and give naphthalene resulting from net elimination of HX and SO2. The X-ray crystal structure of 1 is also reported.

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