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Rings six-member

The use of periodic acid oxidation in structure determination can be illustrated by a case in which a previously unknown methyl glycoside was obtained by the reaction of D-arabinose with methanol and hydrogen chloride. The size of the ring was identified as five-membered because only one mole of periodic acid was consumed per mole of glycoside and no formic acid was produced. Were the ring six-membered, two moles of periodic acid would be required per mole of glycoside and one mole of formic acid would be produced. [Pg.1060]

The chemistry of cyclophosphazanes is dominated by four-membered rings six-membered P3N3 rings are far less common. The first examples of cyclotri-phosphazanes (MeNPX)3 (X = Cl, Br) were prepared by the cyclocondensation... [Pg.232]

Complex Av. Ni—N (A) Distortion" (A) Five-membered rings Six-membered rings Ref. [Pg.137]

The Robinson annelation is by no means the only ionic reaction that makes six-membered rings. Six-membered rings form easily so trapping a Nazarov intermediate (chapter 35) makes good sense. The Friedel-Crafts-like disconnection 18 suggests a most unlikely cation 19 until we realise that it would be formed in the Nazarov cyclisation of the dienone 20 whose synthesis is discussed in the workbook. [Pg.270]

Cyclic ethers of various ring size polymerize by cationic mechanism, including oxiranes (3-membered), oxetanes (4-membered), oxolanes (5-membered), oxepanes (7-membered), and larger rings. Six-membered cyclic ethers do not polymerize because of the thermodynamic restrictions. Oxiranes may be also polymerized by anionic mechanism, whereas for other groups the cationic polymerization is the only mechanism of polymerization. [Pg.484]

Double bond Five-member ring Six-member ring... [Pg.437]

The biological tests evidenced that the most potent analogues were those with a five-membered heterocycle on the bridge, which maintain a proper arrangement of both aromatic moieties, while the remaining derivatives, that is, substituted five-membered rings, six-membered rings, fused bicyclic systems and open derivatives, were much less potent. [Pg.99]

Table 1 displays rate data for alkoxyamine-termi-nated polymers and low molecular model compounds and shows some important trends. At about the same temperature, the dissociation rate constants Ad of alkoxyamines (Schemes 12 and 30) with the same leaving radical (polystyryl, 1-phenylethyl) increase in the order 3 (TEMPO) < 6 < 8 (DEPN) < 1 (DBNO) by a factor of about 30. Acrylate radicals dissociate markedly slower than styryl radicals from 1 (DBNO), but there is no appreciable difference for 8 (DEPN). The dependence of Ad on the nitroxide structure has been addressed by Moad et al.104 They found the order five membered ring < six membered ring < open chain nitroxides and pointed out additional steric (compare 3 and 6) and polar effects. [Pg.294]

A solvent effect has been observed in the DIBAH reduction of the bicyclic 1,3-dioxane 2.51 [IM3] (Figure 2.25). In CHCI3 or CHjClj, the irons isomer 2.53 is predominantly formed, while in THF, the cis isomer 2.52 is the major product. With AlHBrj in EtjO, the stereoselectivity is even higher [IM3] (Figure 2.25). These results have been interpreted in terms of conformational effects, emphasizing the importance of the size of the acetal ring (six-membered vs. five-membered). [Pg.33]

Several polymerizations of 1,7- and higher diene monomers have been reported, Cyclization to large rings (> six-membered) has been postulated. However, in many examples, cyclization is not quantitative and crosslinked polymers are fonned. Evidence for ring formation comes from kinetic data and, in particular, from the delay in the gel point from that expected (based on the assumptions that no cyclization occurs and that all pendant double bonds are available for crosslinking reactions). One common monomer that is thought to show such behavior is methylene-bis-acrylamide (ring structure not proven). [Pg.193]

Problem 18.56. All of the six-membered cyclic structures are incorrect from the viewpoint of conveying the correct bond angles for the atoms of the ring. Six-membered rings are not flat (Sec. 11.8). They are nonplanar, puckered chair structures which allow the bond angles to be the stable tetrahedral bond angle (109.5°). Draw the o- and /3-anomers of o-glucose in the chair structure. [Pg.370]

Four-membered ring Five-membered ring Six-membered ring... [Pg.34]


See other pages where Rings six-member is mentioned: [Pg.452]    [Pg.193]    [Pg.9]    [Pg.32]    [Pg.471]    [Pg.22]    [Pg.456]    [Pg.374]    [Pg.188]    [Pg.360]    [Pg.419]    [Pg.82]    [Pg.187]    [Pg.402]    [Pg.271]    [Pg.119]    [Pg.1023]    [Pg.360]    [Pg.419]    [Pg.329]    [Pg.402]    [Pg.208]    [Pg.107]    [Pg.1113]    [Pg.119]    [Pg.627]    [Pg.638]    [Pg.5344]    [Pg.214]    [Pg.157]   
See also in sourсe #XX -- [ Pg.75 ]




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A Symmetrical Example Conformations of Six-Membered Rings

Alicyclic hydrocarbons, Six-membered Bicyclic ring systems

Alicyclic six-membered rings

Analysis of Six-membered Rings (Kellie and Riddell)

Aromatic six-membered rings

Aromatization of six-membered rings

Asymmetric Hydrogenation of Six-Membered Ring Heteroarenes

Azadienes six-membered ring heteroaromatic

Chair-Boat Interconversion of Six-Membered Rings in the Solid

Chelate six-membered ring

Chemistry five- and six-membered rings

Compounds containing Fused Five- and Six-Membered Rings

Compounds with an Additional Nitrogen in the Six-Membered Ring

Conformational equilibria in nitrogen-containing saturated six-membered rings

Conformational equilibria in nitrogencontaining saturated six-membered rings

Conformational equilibria in saturated six-membered rings

Conformations of the Six-Membered Rings

Enantioselective Organocatalyzed Synthesis of Six-Membered Rings

Five- and Six-Membered Ring Alkaloids

Five- and Six-Membered Unsaturated Rings

Five- and Six-membered-ring Compounds

Five- and six-membered rings with two

Five-and Six-Membered Ring Forms

Five-and six-membered rings

Fluorinated six-membered rings

Formation by Six-Membered Ring Systems

Formation of Six-Membered (and Larger) Rings

Formation of six-membered rings - Diels-Alder reactions

Fused Five- and Six-Membered Rings

Fused Systems containing Two Six-Membered Rings

Fused six-membered rings

Geminal coupling in six-membered rings

Halogenation six- and seven-membered rings

Heterocycles six-membered ring

Heterocyclic synthesis six-membered rings

In six-membered rings

Involving other than five and six-membered rings

Lactones six-membered ring

New six-membered rings

Nitrile imines six-membered rings

Nitrogen heterocycles six-membered rings

Nitrogen-bridged six-membered ring

Nitrogen-bridged six-membered ring systems

Nitrogen-containing six-membered rings

Non-Chair Conformations of Six-Membered Rings (Kellie and Riddell)

Nucleophilic substitution on six-membered rings

Of pyrazoles condensed to heteroaromatic five- and six-membered rings

Of six-membered rings

Other Aromatic Six-Membered Ring Heterocyclics

Other Six-Membered Ring Systems

Other Six-membered Ring Synthesis

Other Syntheses of Six-membered Rings

Other six-and seven-membered rings

Putting more nitrogen atoms in a six-membered ring

Pyrazoles condensed to heteroaromatic five- and six-membered rings

Pyrazoles condensed to heteroaromatic fiveand six-membered rings

Quinones with a Condensed Six-Membered Ring

Reactions Leading to the Formation of Six-Membered Rings

Reactions to form six-membered rings

Reactivity of Six-membered Rings

Rearrangements in Six-Membered Heteroaromatic Rings

Ring Expansion into Six-Membered Heterocycles

Ring Systems of more than Six Members Containing

Rings Other Than Six-Membered

Rings of More Than Six Members

Rings six-membered

Rings with More Than Six Members

Saturated Six-Membered Rings with Two Heteroatoms

Saturated six-membered ring

Selenophens Fused to Six-membered Heterocyclic Aromatic Rings

Six- and Seven-membered Rings

Six-, seven-, nine- and ten-membered rings

Six-Membered Aromatic Ring Construction

Six-Membered Heterocycles Fused to One Benzene Ring

Six-Membered Rings Containing Two Hetero Atoms Fused to One Benzene Ring

Six-Membered Rings Diels-Alder Reactions

Six-Membered Rings containing Oxygen or Sulphur

Six-Membered Rings with Three Heteroatoms

Six-Membered Rings with Two Heteroatoms

Six-membered Nitrogen- and Oxygen-containing Rings

Six-membered Rings containing more than One Nitrogen

Six-membered Rings with More than One Oxygen

Six-membered aromatic heterocycles can have oxygen in the ring

Six-membered heteroaromatic ring

Six-membered heterocyclic rings

Six-membered oxygen-containing rings

Six-membered oxygen-containing rings saturated, analysis

Six-membered ring alkene

Six-membered ring derivatives

Six-membered ring formation

Six-membered ring heterocycles containing one oxygen atom

Six-membered ring heterocycles with one

Six-membered ring phosphorus

Six-membered ring structures

Six-membered ring systems

Six-membered ring systems Pyridines and benzo derivatives

Six-membered ring systems, nitrogen

Six-membered rings Containing two nitrogens

Six-membered rings Dichlorotris

Six-membered rings Friedel-Crafts reaction

Six-membered rings aldol reaction cascade

Six-membered rings benzene

Six-membered rings metal complexes

Six-membered rings pyrimidine

Six-membered rings reactions

Six-membered rings synthesis

Six-membered rings, characteristics

Six-membered rings, sugars

Six-membered-ring carbocyclics

Stereochemical control in six-membered rings

Structure of Six-membered Rings

Syntheses via BCD intermediates with a six-membered ring

Synthesis of Six-Membered Rings (Diels-Alder Reaction)

Synthesis of six-membered ring

The Hebrew University, Jerusalem, Israel Six-Membered Ring Systems Pyridine and Benzo Derivatives

Thiophen Fused to Six-membered Heteroaromatic Rings

Thiophens Fused to Six-Membered Heteroaromatic Rings

Transformation of a Six-membered Ring

Two Fused Six-Membered Rings

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