Octa-acid

The template plays an important role in the formation of capsule F because no directional non-covalent bonds such as H-bonding and M-L interactions are involved in the self-assembly process. In addition, an external hydrophobic template is necessary because aqueous solvent does not template the formation of F. Capsule F consists of two octa-acid, deep-cavity cavitands with a pseudo-conical hydrophobic cavity (Figure 6.6a). The eight carboxylic acid groups are located at the periphery of the cavitand, thereby inducing... 

This has been exploited to probe the dynamics of different guest molecules included within the capsule formed by self-assembly of a deep cavitand trivially known as octa acid (7). Inclusion of an asymmetrical guest such... 

Figure 6 Partial H NMR spectra of octa acid 7 in D2O. (a) Free 7, (b) 4,4 -dimethylstilbene 72 and (c) 4-methylstilbene 72. Host assignments are shown in the inset. Methyl groups are from the guest. (Reproduced from Ref. 9. American Chemical Society, 2010.)...

Figure 23 Hydrophobically driven dimerization of water-soluble octa-acid cavitand encapsulating apolar templating guests.

Porel M, Jayaraj N, Kaanumalle LS, Maddipatla MVSN, Parthasarathy A, Ramamurthy V. Cavitand octa acid forms a nonpolar capsuleplex dependent on the molecular size and hydrophobicity of the guest. Langmuir 2009 25 3473-81. 

A series of liquid crystalline esters of 2,3,9,10,16,17,23,24-phthalocyanine octa-carboxylic acid have been synthesized by Dulog and Gittinger [205]. The octacarbox-ylic acid is prepared [206] from benzenetet-racarbonitrile (tetracyanobenzene) [205] in two steps cyclization under standard conditions, and hydrolysis of phthalocyanine-octacarbonitrile with potassium hydroxide in triethylene glycol. The octa-acid is ester-ified with an alkyl bromide using DBU in acetonitrile (Scheme 52). The mesophase behaviour is essentially the same for all the derivatives studied (pentyl to dodecyl), with the materials exhibiting an hexagonal co-... 

COT is prepared by the polymerization of ethyne at moderate temperature and pressure in the presence of nickel salts. The molecule is non-planar and behaves as a typical cyclic olefin, having no aromatic properties. It may be catalytically hydrogenated to cyclo-octene, but with Zn and dil. sulphuric acid gives 1,3,6-cyclooclairiene. It reacts with maleic anhydride to give an adduct, m.p. 166 C, derived from the isomeric structure bicyclo-4,2,0-octa-2,4,7-triene(I) ... 

Lactose (hydrated). Lactose (anhydrous) 2031 223 + 52-5 200 — Octa-acetate, a- 152, P- 90 mucic acid, 213... 

Octasodium salt of octa-4,5-dicarboxyphthalocyanin cobalt(II) combined with ascorbic acid (teraphthal) as a new drug for binary catalytic therapy of malignant tumors 98MI57. 

Oxidation of 8-( 1 -methylethenyl)-2-oxo-7-thia-1 -azabicyclo[4.3.0]octa-3,5-diene-5,8-dicarboxylate (104) and its 3,4-dihydro derivative in CHCI3 with peracids (w-chloroperbenzoic acid and CF3CO3H) at room temperature gave diethyl 3-methyl-6-oxo-2/7,6//-pyrido[2,l-Z)][l,3]thiazine-4,9-dicarboxylate and its 7,8-dihydro derivative in 66% and 56% yield, respectively (99JCS(P1)3569). 

A) A solution of (SMI (320 mg) in trifluoroacetic acid (7 ml) was kept under nitrogen at room temperature for 15 minutes. Ether (100 ml) was added and the precipitate filtered, washed thoroughly with ether and dried. This material (280 mg) was added to concentrated sulfuric acid (20 ml), cooled at -20°C. The solution was kept in the dry ice-acetone bath at -20°C for 75 minutes. The sulfuric acid solution was poured into ice water (80 ml). The precipitate was centrifuged, resuspended in ice water (30 ml) and 4N sodium hydroxide was added until a clear solution was obtained. After reacidification to pH 4 with dilute sulfuric acid, the precipitate formed was centrifuged, washed twice with ice water and dried. Yield 155 mg. Chromatograph of DEAE Sephadex (with ammonium carbonate buffer) yielded the desired octa-peptide sulfate ester 30 mg. 

Bicyclo[2.2.1]hepta-2,5-diene, nitrosyl chloride adduct, 46, 74 reaction with acetic acid to yield nortricyclyl acetate, 46, 74 Bicyclohexyl, 46, 61 Bicyclohexylidene, 47, 34 ejSO-e s-BlCYCLO[3.3.0]OCTANE-2-CAR-BOXYLIC ACID, 47, 10 Bicyclopentadienylidene, octa-chloro-, 46,93... 

Palladous chloride in preparation of hydrogenation catalyst, 46, 89 Paraformaldehyde, conversion to form aldoximc, 46,13 Pelargonyl fluoride 46, 6 1-Pentalenecaeboxylic acid, octa hydro-, 47,10... 

The solid-state structure of tetrabutylbis(2,3 4,6-diisopropylidene-2-keto-L-gulonato)distannoxane has been determined. The [Bu2Sn(IV)] complex of D-lactobionic acid also proved to be oligomeric, containing octa- (within the chain) and pentacoordinated (at the end of the chain) Sn centers in a ratio of 2 4. ... 

In a few cases, the synthesis was directed towards well-defined oligomers (dimers, trimers, etc.). The synthesis of bis(5,7,3, 4 -tetra-0-benzyl)-EC 4/1,8-dimer from 5,7,3, 4 -tetra-0-benzyl-EC and 5,7,3, 4 -tetra-0-benzyl-4-(2-hydroxyethoxy)-EC was described by Kozikowski et al. [41]. This compound exhibited the ability to inhibit the growth of several breast cancer cell fines through the induction of cell cycle arrest in the Gq/Gi phase. Analogously, procyanidin-B3, a condensed catechin dimer, has been obtained through condensation of benzylated catechin with various 4-0-alkylated flavan-3,4-diol derivatives in the presence of a Lewis acid. This reaction led to protected procyanidin-B3 and its diastereomer. In particular, octa-O-benzylated procyanidin-B3 has been produced with high levels of stereoselectivity and in excellent isolation yields [42]. 

Bayer (1997) has claimed that in a water-CH2Cl2 system, using water soluble Pd(OAc)2 -triphenylphosphine trisulphonic acid catalyst, octa-2,7-dienyl-l-amine and octa 1,7-dienyl -3-amine can be obtained by telomerization of butadiene with ammonia. 

Dimalone [bicyclo-(2.2.1)-5-heptene-2,3-dicarboxylic acid dimethyl ester] and Octa-cide 264 [the V-octyl imide of bicyclo-(2.2.1)-5-heptene-2,3-dicarboxylic acid] do produce a red color with an absorption maximum in the same region as that obtained in the analysis of Compound 118. However, because Dimalone is an insect repellent and Octacide 264 is a pyrethrum synergist, neither of these products is likely to be encountered in commercial mixtures of Compound 118. The response to the colorimetric test for Compound 118 of some chemicals commonly used for insect control is listed in Table V. 

This conclusion10 has been reached mainly from crystallographic studies on chitin and on acetylchitobiose obtained from chitin by acetoly-sis.107 The chitobiose was isolated in the form of its crystalline octa-acetate which could also be obtained108 by acetylation of the hydrolyzate produced by the action of fuming hydrochloric acid on chitin. A hen-decaaeetylchitotriose also was obtained by this procedure. 

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