Identification of impurities affecting commercial ethylene glycol UV transmittance

As a raw material for making polyesters, ethylene glycol has a special specification of UV transmittance. At present, ethylene glycol produced by some plants still has low UV transmittance rendering it unsuitable for use in polyester production. In this paper, a method was developed for the identification of the impurities that cause commercial ethylene glycol to have low UV transmittance, using solid-phase extraction (SPE) and some analytical techniques such as high-performance liquid chromatography, gas chromatography-mass spectrometry and gas chromatography-Fourier transform infrared spectroscopy. The major UV-absorbing impurities were identified as some alkyl homologues of 2-hydroxycyclopent-2-en-1-one, including 2-hydroxy-3,5-dimethylcyclopent-2-en-1-one, 2-hydroxy-3-methylcyclopent-2-en-1-one, 2-hydroxy-3,4-dimethylcyclopent-2-en-1-one, 2-hydroxy-3-ethyl-4-methylcyclopent-2-en-1-one and 2-hydroxy-3-ethylcyclopent-2-en-1-one. Their concentrations were estimated to be less than 2 microg ml(-1). It is believed that with the above results, ethylene glycol-producing plants might make process improvements to remove these impurities more effectively and more easily.     

A bicyclo[3.2.0]hept-3-en-6-one approach to prostaglandin intermediates

[reaction:see text] The substituted cyclopentanic structures, 6-benzyloxymethyl-7-hydroxy-2-oxabicyclo [3.3.0]octan-3-one (1), a Corey lactone derivative, and 6-exo-benzyloxymethyl-2-oxabicyclo[3.3. 0]oct-7-en-3-one (2), have been obtained stereoselectively through the bicyclo[3.2.0]hept-3-en-6-one approach via 5-benzyloxymethyl-3-hydroxy-6-heptenoic acid, easily accessible from the inexpensive monoprotected cis-2-butene-1,4-diol.     

Enantiomeric separation of novel anticancer agent 5-hydroxy-3-(4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)-cyclopent-2-en-1-one

The enantiomers of 5-hydroxy-3-(4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)-cyclopent-2-en-1-one, a novel anticancer agent, were separated by derivatisation with caronaldehyde, separation of the resulting diastereoisomers of the corresponding esters by silica gel column chromatography and regeneration of alcohols (S)-5-hydroxy-3-(4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)-cyclopent-2-en-1-one and (R)-5-hydroxy-3-(4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)-cyclopent-2-en-1-one under aqueous conditions. The absolute configuration of the enantiomers was determined by 1H NMR studies of the corresponding Mosher esters. Alternatively, the enantiomers were separated by preparative HPLC to collect the (S)- and (R)-5-hydroxy-3-(4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)-cyclopent-2-en-1-ones with high purity which was comparable with that obtained by the chemical method. The details of these methods have been presented herein.     

Photochemical reactivity of α,β-unsaturated δ-lactams: Synthesis of seco-steroids. Photochemical reactions. XIII [1]

The UV. irradiation of 17 β-hydroxy-2-aza-4-androsten-3-one (1) , N-methyl-17 β-hydroxy-2-aza-4-androsten-3-one (3) , 17 β-hydroxy-4-aza-5 β-androst-1-en-3-one (2) and N-methyl-17 β-hydroxy-4-aza-5 β-androst-1-en-3-one (4) , gives rise to 1,10-seco (from 1 and 3 ) and 5, 10-seco (from 2 and 4 ) steroids.     

Synthesis of 19-hydroxypregn-4-en-20-one and 19-hydroxy-5β-pregn-3-en-20-one that selectively bind to membrane progesterone receptors,and assessment of their immunomodulatory effects

Russian Chemical Bulletin - A new approach to the synthesis of isomeric 19-hydroxypregn-4-en-20-one (1) and 19-hydroxy-5β-pregn-3-en-20-one (2), the selective ligands of membrane progesterone...     

Selectivity in cycloadditions: Crystal and molecular structure of (1a,4β,5a)-1,5-diacetyl-4-hydroxy-4-methylbicyclo[3.1.0]Hexan-2-one

The stereochemistry of (1a,4β,5a)-1,5-diacetyl-4-hydroxy-4-methylbicyclo[3.1.0]hexan-2-one, the main cycloadduct of 2,3-diacetyl-4-hydroxy-4-methylcyclopent-2-en-1-one and diazomethane, was unambiguously established from a single crystal X-ray analysis.     

4个天然1,7-二芳基庚烷类化合物的合成

合成了4个天然1,7-二芳基庚烷类化合物:1-(4′-羟基-3′-甲氧基苯基)-7-(4″-羟基苯基)-5-羟基-3-庚酮(1),1-(4′-羟基-3′-甲氧基苯基)-7-(4″-羟基苯基)-4-庚烯-3-酮(2),1-(3′,4′-二羟基苯基)-7-(4″-羟基苯基)-5-羟基-3-庚酮(3),1-(3′,4′-二羟基苯基)-7-(4″-羟基苯基)-4-庚烯-3-酮(4).化合物1,2,4为首次合成.     

A stereospecific synthesis of chaloxone

Chaloxone, 5-hydroxy-3-methoxy-7-oxabicyclo[4.1.0]hept-3-en-2-one, has been synthesised from benzoquinone via a diepoxide.     

Prostanoids: LXXXVII. Synthesis of 3-Hydroxy-2-phenylsulfonyl-2-cyclopentenone and Its Ethylene Acetal

By oxidation of 3-phenylmercapto-2-chloro-4,4-ethylenedioxycyclopet-2-en-1-one with H₂O₂ in AcOH (or with m-ClC₆H₄CO₃H in CH²Cl²2) was obtained 2-chloro-3-phenylsulfonyl-4,4-ethylenedioxycyclopent-2-en-1-one which on reduction with NaBH₄ or LiAlH₄ afforded respectively 3-hydroxy-2-phenylsulfonylcyclopent-2-en-1-one and its ethyleneketal.     

Reactions of C(6)F(5)Li with tetracyclone and 3-ferrocenyl-2,4, 5-triphenylcyclopentadienone: An (19)F NMR and X-ray crystallographic study of hindered pentafluorophenyl rotations

Tetracyclone, 2a, reacts with C(6)F(5)Li to yield 2-pentafluorophenyl-2,3,4,5-tetraphenylcyclopent-3-en-1-one, 7, and 5-hydroxy-5-pentafluorophenyl-1,2,3,4-tetraphenylcyclopentadiene, 8, as the result of 1,6 and 1,2 additions, respectively. In contrast, treatment of 3-ferrocenyl-2,4,5-triphenylcyclopentadienone, 2b, with lithiopentafluorobenzene leads to 4-ferrocenyl-4-pentafluorophenyl-2, 3,5-triphenylcyclopent-2-en-1-one, 9, and 5-hydroxy-5-pentafluorophenyl-2-ferrocenyl-1,3, 4-triphenylcyclopentadiene, 10, the products of 1,4 and 1,2 addition, respectively. The structures of 7-9 have been established by X-ray crystallography, and the barriers to rotation (19-21 kcal mol(-)(1)) of the pentafluorophenyl groups in 8-10 have been studied by variable-temperature (19)F NMR. Nucleophilic attack at the ferrocenyl-bearing carbon in 2b is rationalized in terms of a zwitterionic structure in which the positive charge of the "cyclopentadienyl cation" is delocalized onto the iron atom in the organometallic substituent.     

Synthesis and screening of aromatase inhibitory activity of substituted C19 steroidal 17-oxime analogs

The synthesis and aromatase inhibitory activity of androst-4-en-, androst-5-en-, 1β,2β-epoxy- and/or androsta-4,6-dien-, 4β,5β-epoxyandrostane-, and 4-substituted androst-4-en-17-oxime derivatives are described. Inhibition activity of synthesized compounds was assessed using aromatase enzyme and [1β-3H]androstenedione as substrate. Most of the compounds displayed similar to or more aromatase inhibitory activity than formestane (74.2%). 4-Chloro-3β-hydroxy-4-androsten-17-one oxime (14, 93.8%) showed the highest activity, while 4-azido-3β-hydroxy-4-androsten-17-one oxime (17, 32.8%) showed the lowest inhibitory activity for aromatase.     

Totalsynthese von Steroiden. 1. Mitteilung. rac-17β-Hydroxydes-A-androst-9-en-5-on

In connection with earlier work on the synthesis of 9β, 10α-steroids, a new and practical synthesis of rac-17α-hydroxy-des-A-androst-9-en-5-one ( 19 ) has been developed, based on a novel stereoselective condensation of 7-hydroxy-1-nonen-3-one ( 3 ) with 2-methyl-cyclopentane-1, 3-dione ( 9 ) and subsequent transformations of the resulting tricyclic diene ether 12 .     

Transformed steroids. 118. The geometric isomerism of 20-ethoxycarbonylhydrazones of 3β-hydroxy-16,17α-cyclopropanopregn-5-en-20-one

In the reaction of the 3β-acetate of 3β-hydroxy-3′H-cyclopropano[16,17α]pregn-5-en-20-one (I) with ethoxycarbonylhydrazine in AcOH at 20°C (exposure for up to 6 days), a chromatographically separable equilibrium mixture of the 20Z-ethoxycarbonylhydrazone of 3β-acetoxy-3′H-cyclopropano[16,17α]pregn-5-en-20-one (II), with mp 190–195°C, and the 20E-ethoxycarbonylhydrazone of 3β-acetoxy-3′H-cyclopropano[16,17α]pregn-5-en-20-one (III) with mp 186–193°C (ratio 2:1) is obtained. The geometric isomers obtained are distinguished by IR, PMR, and CD spectroscopy. It has been shown that the observed geometric isomerism takes place via an intermediate enehydrazine form.     

2,6,7-Trihydroxy-4,9-dioxodeca-2,5,7-trienoic and 2-hydroxy-2-(3-hydroxy-4-methyl-2,5-dioxocyclopent-3-en-1-ylidene)acetic acid esters: Synthesis and structural specificity

Claisen condensation of acetone and butan-2-one with diethyl oxalate in the presence of metallic sodium leads to the formation of ethyl 2,6,7-trihydroxy-4,9-dioxodeca-2,5,7-trienoate and ethyl 2-hydroxy-2-(3-hydroxy-4-methyl-2,5-dioxocyclopent-3-en-1-ylidene)acetate, respectively.     

Antigenotoxic ketosteroid from the red algae Jania adhaerens

A new ketosteroid, 6β,16β-dihydroxycholest-4-en-3-one (1), in addition to the known 6β-hydroxycholest-4-en-3-one (2), 6β-hydroxycholest-4,22-dien-3-one (3) and 16β-hydroxy-5α-cholestan-3,6-dione (4), was isolated from the red alga Jania adhaerens. The structures were assigned on the basis of (1)H- and (13)C-NMR experiments. The new compound (1) was evaluated for its genotoxic and cytotoxic activities and found to possess protective antigenotoxicity in human peripheral blood cells.     

Hydrogen-mediated C-C bond formation: catalytic regio- and stereoselective reductive condensation of alpha-keto aldehydes and 1,3-enynes

Hydrogenation of 1,3-enynes in the presence of alpha-keto aldehydes using cationic Rh(I) catalysts enables regio- and stereoselective reductive coupling to the acetylenic terminus of the enyne to afford (E)-2-hydroxy-3,5-dien-1-one products. Reductive condensation of 1-phenyl but-3-en-1-yne 1a with phenyl glyoxal 2a performed under an atmosphere of D(2) provides the product of mono-deuteration, (E)-2-hydroxy-3-deuterio-3,5-dien-1-one deuterio-3a, in 85% yield. Competition experiments involving catalytic hydrogenation of phenyl glyoxal in the presence of equimolar quantities of 1,4-diphenylbutadiene and 1,4-diphenylbut-3-en-1-yne 10a, as well as 1,4-diphenylbut-3-en-1-yne 10a and 1,4-diphenylbutadiyne, are chemoselective for coupling to the more highly unsaturated partner, suggesting a preequilibrium involving precoordination and exchange of the pi-unsaturated pronucleophiles with the catalyst prior to C-C bond formation, as well as a preference for coordination of the most pi-acidic reacting partner, as explained by the Dewar-Chatt-Duncanson model for alkyne coordination.     

Reactions of tri- and hexafluoroacetylacetones and 4-ethoxy-1,1,1-trifluorobut-3-en-2-one with 2-aminobenzohydrazide

Reactions of 1,1,1-trifluoropentane-2,4-dione and 1,1,1,5,5,5-hexafluoropentane-2,4-dione with 2-aminobenzohydrazide afforded (2-aminophenyl)[5-hydroxy-3-methyl-5-(trifluoromethyl)- and (2-aminophenyl)[ 5-hydroxy-3,5-bis(trifluoromethyl)-4,5-dihydropyrazol-1-yl]methanones, respectively. 4-Ethoxy-1,1,1- trifluorobut-3-en-2-one reacted with 2-aminobenzhydrazide to give 2-(trifluoromethyl)-3a,4-dihydropyrazolo-[5,1-{ptb}]quinazolin-9(3{ptH})-one.     

Pyrimidines

The reaction of phenylacetone with benzylidenebisurea (BBM) has given 2-hydroxy-4, 5-diphenyl-6-styryl-3, 4-dihydropyrimidine (I). The structure of I has been confirmed by its independent synthesis from 1, 4diphenylbut-3-en-2-one and BBM and also by a number of subsequent transformations.For part XVIII, see [1]     

Synthesis of 5-(trifluoromethyl)cyclohexane-1,3-dione and 3-amino-5-(trifluoromethyl)cyclohex-2-en-1-one: new trifluoromethyl building block

A simple synthesis of 5-(trifluoromethyl)cyclohexane-1,3-dione and 3-amino-5-(trifluoromethyl)cyclohex-2-en-1-one from the sodium salt of methyl or ethyl-4-hydroxy-2-oxo-6-(trifluoromethyl)cyclohex-3-en-1-oate is demonstrated. The compounds represent highly functionalized reactive intermediates for the synthesis of organic and heterocyclic compounds containing a trifluoromethyl group.     

Oxidation of Steroidal 5-En-3β-ol with Pyridinium Chlorochromate: Isolation of Key Intermediate,Steroidal 6β-Hydroxy-4-en-3-one

The PCC oxidation of 5-en-3β-ol steroids proceeds to 4-en-3,6-dione through the intermediate 5-en-3-one. The isolation of another key intermediate, steroidal 6β-hydroxy-4-en-3-one guides an understanding of the mechanism involved.