A simple and direct method of cyclization for the synthesis of a 10-membered ring

1984 ◽  
Vol 62 (11) ◽  
pp. 2395-2398 ◽  
Author(s):  
Pierre Deslongchamps ◽  
Serge Lamothe ◽  
Ho-Shen Lin
Keyword(s):  
Direct Method ◽  
Membered Ring ◽  
Aliphatic Chain ◽  
Cyclic Compounds ◽  
Allylic Chloride ◽  
Anion Displacement

The malonate anion displacement of allylic chloride in a ten-carbon aliphatic chain containing one additional unsaturation center yields 10-membered cyclic compounds.

A simple and direct method of cyclization for the synthesis of 10-membered rings

1987 ◽  
Vol 65 (6) ◽  
pp. 1298-1307 ◽  
Author(s):  
Pierre Deslongchamps ◽  
Serge Lamothe ◽  
Ho-Shen Lin
Keyword(s):  
Direct Method ◽  
High Dilution ◽  
Allylic Chloride ◽  
Anion Displacement

Ten-membered rings containing two unsaturations are produced without the use of high dilution techniques by the intramolecular malonate anion displacement of an allylic chloride.

7α-Acetoxydihydronomilin: isolation, spectra, and crystal structure

1978 ◽  
Vol 56 (7) ◽  
pp. 1020-1025 ◽  
Author(s):  
Farid R. Ahmed ◽  
Angs Ng ◽  
Alex G. Fallis
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Least Squares ◽  
Furan Ring ◽  
Lactone Ring ◽  
Direct Method ◽  
Membered Ring ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray ◽  
Twist Boat

Methanol extraction of the ground seeds of Uncaria Gambier Roxb. followed by chromatography afforded a crystalline C30H38O10 terpene. This has been shown by X-ray analysis to be 7α-acetoxydihydronomilin. The crystals are orthorhombic, P212121, a = 13.158(2), b = 17.092(2), c = 12.689(2) Å, Z = 4, dx = 1.300, do = 1.300 g cm−3. The structure has been determined by the direct method and Fourier syntheses, and refined by block-diagonal least-squares to R = 0.042 for 2621 observed reflexions. The molecule contains a seven-membered lactone ring A, three six-membered rings B, C, D, a three-membered ring E, a furan ring F, and two acetate groups. A and B are chair, C is twist-boat, D is 1,3-diplanar, while E and F are planar. The A/B, A/C, C/D junctions are trans, D/E is cis, and F is linked to D by an equatorial C—C bond. The two acetate groups are in axial positions on A and B and are cis to each other. The O atom forming the apex of the three-membered ring is wedged between two H atoms and their parent C atoms at short intramolecular distances O … H = 2.28(2) and 2.28(3), and O … C = 2.623(3) and 2.668(4) Å. No intermolecular hydrogen bonding is indicated.

scholarly journals Conformational studies of aliphatic secondary ozonides (propene, 1-butene and 1-heptene) by means of FTIR spectroscopy

2006 ◽  
Vol 4 (4) ◽  
pp. 578-591 ◽  
Author(s):  
Ruta Bariseviciute ◽  
Justinas Ceponkus ◽  
Alytis Gruodis ◽  
Valdas Sablinskas
Keyword(s):  
Theoretical Calculations ◽  
Membered Ring ◽  
Aliphatic Chain ◽  
Equatorial Position ◽  
Ir Absorption ◽  
Stable Conformer ◽  
Gaseous Products ◽  
Ir Absorption Spectra ◽  
Secondary Ozonide ◽  
The One

AbstractOzonization reaction of simple alkenes was studied by means of FT infrared absorption gas spectroscopy. The reaction was performed at 95 K in neat films of the reactants. IR absorption spectra of the gaseous products were recorded. The spectra were analyzed combining experimental results with theoretical calculations performed at B3LYP 6-311++G (3df, 3pd) level. We found that among all theoretically predicted conformers of propene secondary ozonide, only one which has the O-O half-chair configuration for the five membered ring and the radical attached in the equatorial position was present in the sample. Samples of 1-butene and 1-heptene secondary ozonides consist from two conformers of very similar energy (ΔH=0.3 kJ/mol). The most stable conformer for both ozonides is the one with O-O half-chair configuration of the five membered ring and the radical attached in equatorial position and the aliphatic chain in gauche position. The second stable conformer has the aliphatic chain in anti position.

scholarly journals Enantio- and Diastereoselective Suzuki-Miyaura Coupling with Racemic Bicycles

2019 ◽  
Author(s):  
Friedrich Wieland Goetzke ◽  
Mike Mortimore ◽  
Stephen P. Fletcher
Keyword(s):  
Cross Coupling ◽  
Boronic Acids ◽  
Membered Ring ◽  
Starting Material ◽  
Mechanistic Studies ◽  
Relative Stereochemistry ◽  
Allylic Chloride

Herein we describe a rhodium-catalyzed enantio- and diastereoselective Suzuki-Miyaura cross-coupling between racemic fused bicyclic allylic chlorides and boronic acids. The highly stereoselective transformation allows for the coupling of aryl-, heteroaryl- and vinyl boronic acids and gives access to functionalized bicyclic cyclopentenes which can be converted to other five-membered ring scaffolds with up to five contiguous stereocenters. Preliminary mechanistic studies suggest that these reactions occur with overall retention of the relative stereochemistry and is enantioconvergent for pseudo-symmetric allylic chloride starting materials. In addition, a bicyclic allylic chloride starting material without pseudo-symmetry undergoes a highly enantioselective regiodivergent reaction.

Synthesis of renewable C–C cyclic compounds and high-density biofuels using 5-hydromethylfurfural as a reactant

2020 ◽  
Vol 22 (8) ◽  
pp. 2468-2473 ◽  
Author(s):  
Taimei Cai ◽  
Qiang Deng ◽  
Hailong Peng ◽  
Jin Zhong ◽  
Rui Gao ◽  
...  
Keyword(s):  
Membered Ring ◽  
High Density ◽  
Cyclic Compounds

Renewable C–C six-membered ring compound and high-density biofuel are synthesized using 5-hydromethylfurfural as a reactant.

The Retention of Six-, Seven-, Eight-, and Twelve-Membered Ring Molecules of Type SexS y in Reversed-Phase HPLC. Prediction of Retention for Unknown SexS y Heterocycles and Analysis of Sulfur-Selenium Melts

1990 ◽  
Vol 45 (9) ◽  
pp. 1282-1290 ◽  
Author(s):  
Ralf Steudel ◽  
Eva-Maria Strauss ◽  
Detlef Jensen
Keyword(s):  
Reversed Phase ◽  
Membered Ring ◽  
Molar Ratio ◽  
Reversed Phase Hplc ◽  
Ring Molecules ◽  
Linear Relationships ◽  
Size Number ◽  
Prediction Of Retention ◽  
Cyclic Compounds ◽  
Prediction Of Retention Times

The HPLC retention times of 25 cyclic compounds of type SexSy, (x = 0 · · · 8; y = 0 · · · 12) have been measured under identical conditions and are used to evaluate the factors which determine the retention. Linear relationships are derived for the dependence of retention (Ink'; k′ = capacity factor) on ring size, number of Se atoms, and number of SeS bonds per molecule for six-, seven-, eight-, and twelve-membered SexSy rings. These relationships allow the prediction of retention times for all SexSy heterocycles of these ring sizes (ca. 100 compounds). The results are applied to the qualitative analysis of mixed sulfur-selenium melts of two compositions: at a molar ratio of S : Se = 8.7 twenty-one HPLC signals have been observed for the CS2 extract of the quenched melt and assigned to SexSy rings of sizes 6··· 12. At S : Se = 0.33 mainly six-, seven-, and eight-membered species with cumulated Se atoms have been found.

scholarly journals Enantio- and Diastereoselective Suzuki-Miyaura Coupling with Racemic Bicycles

2019 ◽  
Author(s):  
Friedrich Wieland Goetzke ◽  
Mike Mortimore ◽  
Stephen P. Fletcher
Keyword(s):  
Cross Coupling ◽  
Boronic Acids ◽  
Membered Ring ◽  
Starting Material ◽  
Mechanistic Studies ◽  
Relative Stereochemistry ◽  
Allylic Chloride

Herein we describe a rhodium-catalyzed enantio- and diastereoselective Suzuki-Miyaura cross-coupling between racemic fused bicyclic allylic chlorides and boronic acids. The highly stereoselective transformation allows for the coupling of aryl-, heteroaryl- and vinyl boronic acids and gives access to functionalized bicyclic cyclopentenes which can be converted to other five-membered ring scaffolds with up to five contiguous stereocenters. Preliminary mechanistic studies suggest that these reactions occur with overall retention of the relative stereochemistry and is enantioconvergent for pseudo-symmetric allylic chloride starting materials. In addition, a bicyclic allylic chloride starting material without pseudo-symmetry undergoes a highly enantioselective regiodivergent reaction.

Über Reaktionen von 3-trifluormethylphenylsubstituierten silicium-und zinnorganischen Verbindungen / Reactions of 3-Trifluoromethylphenyl Substituted Silicon and Tin Organic Compounds

1978 ◽  
Vol 33 (7) ◽  
pp. 759-762 ◽  
Author(s):  
Herbert W. Roesky ◽  
Klaus Ambrosius
Keyword(s):  
Organic Compounds ◽  
Nmr Spectra ◽  
Membered Ring ◽  
Spiro Compound ◽  
Cyclic Compounds ◽  
Substituted Urea

AbstractSeveral routes were investigated for the preparation of 3-CF3C6H4N[Si(CH3)3]2 2 and 3-CF3C6H4N[Sn(CH3)3]2 3. The latter compound reacts with 3-CF3C6H4NCO to yield [3-CF3C6H4(CH3)3SnN]2CO 4. A substituted urea 5 is also formed from [(CH3)3Si]2NCH3 and 3-CF3C6H4NCO. 5 is used for the preparation of cyclic compounds, with S2Cl2 the ten-membered ring (3-CF3C6H4NCONCH3S2)2 6 is formed. 5 and HN(SO2Cl)2 yield the six-membered ring 3-CF3C6H4NCONCH3(SO2)2NH 7. SeOCl2 and 5 react under formation of a spiro compound (S-CF3C6H4NCONCH3)2Se 8. The compounds were characterized on the basis of mass and 19F NMR spectra.

Sign in / Sign up

Export Citation Format

Share Document