Efficient Synthesis of Diacetoxyiodoarenes via Intramolecular Rearrangement

2019 ◽  
Vol 16 (11) ◽  
pp. 911-914
Author(s):  
De-Jun Zhou ◽  
Yang-Yang Zhai ◽  
Ling-Pu Meng ◽  
Wei-Wei Song ◽  
Xiao Liu ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Efficient Method ◽  
Intramolecular Rearrangement ◽  
Sodium Perborate ◽  
Efficient Synthesis

This study introduces a concise and efficient method for preparing diacetoxyiodoarenes from the corresponding iodoarenes. In the presence of acetic anhydride, iodoarenes were oxidized to diacetoxyiodoarenes by sodium perborate in acetic acid under argon protection at 55°C in ideal yields. Through this method, 10 diacetoxyiodoarenes were obtained smoothly.

An efficient synthesis of pterosin C and other pterosins

1984 ◽  
Vol 62 (10) ◽  
pp. 1945-1953 ◽  
Author(s):  
Kam-Mui Eva Ng ◽  
Trevor C. McMorris
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Methyl Ether ◽  
Sodium Acetate ◽  
Synthetic Route ◽  
Efficient Synthesis ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Cis And Trans

A versatile synthetic route to pterosins, sesquiterpenoid indanones present in bracken, Pteridiumaquilinum, has been developed. The route is exemplified by the synthesis of (2S,3S)-pterosin C by Friedel–Crafts bisacylation of the methyl ether of 2-(2,6-dimethylphenyl)ethanol with methylmalonyl chloride. Demethylation of the resulting 1,3-indandione and reduction with zinc and acetic acid in the presence of acetic anhydride and sodium acetate afforded a mixture of racemic cis and trans isomers of pterosin C diacetate, which was hydrolysed to the corresponding pterosins. Separation and resolution via the S-(+)-α-phenylbutyric esters gave (2S,3S)-pterosin C and (2R,3R)-pterosin C. Other pterosins were prepared as racemates from the 1,3-indandione.

An unusual reaction of a bridged triterpenoid α-diketone with acetic anhydride

1991 ◽  
Vol 56 (12) ◽  
pp. 2917-2935 ◽  
Author(s):  
Eva Klinotová ◽  
Václav Křeček ◽  
Jiří Klinot ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
Spectral Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Condensation Products ◽  
Unsaturated Lactones ◽  
C Nmr

3β-Acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) reacts with acetic anhydride in pyridine under very mild conditions affording β-lactone IVa and γ-lactones Va and VIIa as condensation products. On reaction with pyridine, lactones Va and VIIa undergo elimination of acetic acid to give unsaturated lactones VIIIa and IXa, respectively. Similarly, the condensation of 20β,28-epoxy-21,22-dioxo-18α,19βH-ursan-3β-yl acetate (IIIb) with acetic anhydride leads to β-lactone IVb and γ-lactone Vb; the latter on heating with pyridine affords unsaturated lactone VIIIb and 21-methylene-22-ketone Xb. The structure of the obtained compounds was derived using spectral methods, particularly 1H and 13C NMR spectroscopy; structure of lactone IVa was confirmed by X-ray diffraction.

HSCCC Separation of Three Main Compounds from the Crude Extract of Dracocephalum Tanguticum by Using Dimethyl Sulfoxide as Cosolvent

2020 ◽  
Author(s):  
Xue Yang ◽  
Yongling Liu ◽  
Tao Chen ◽  
Nana Wang ◽  
Hongmei Li ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Ethyl Acetate ◽  
Dimethyl Sulfoxide ◽  
Efficient Method ◽  
Crude Extract ◽  
High Speed ◽  
Glacial Acetic Acid ◽  
Butyl Alcohol ◽  
Preparative Hplc ◽  
Counter Current

Abstract Separation of natural compounds directly from the crude extract is a challenging work for traditional column chromatography. In the present study, an efficient method for separation of three main compounds from the crude extract of Dracocephalum tanguticum has been successfully established by high-speed counter-current chromatography (HSCCC). The crude extract was directly introduced into HSCCC by using dimethyl sulfoxide as cosolvent. Ethyl acetate/n-butyl alcohol/0.3% glacial acetic acid (4: 1: 5, v/v) system was used and three target compounds with purity higher than 80% were obtained. Preparative HPLC was used for further purification and three target compounds with purity higher than 98% were obtained. The compounds were identified as chlorogenic acid, pedaliin and pedaliin-6″-acetate.

Efficient Synthesis of DiAZT Triphosphate

2014 ◽  
Vol 662 ◽  
pp. 59-62
Author(s):  
Shan Shan Gong ◽  
Qi Sun
Keyword(s):  
Efficient Method ◽  
Good Yield ◽  
Efficient Synthesis

A facile and efficient method for the synthesis ofP1,P3-dizidovudine-5′,5′-triphosphate has been developed. The coupling of zidovudine diphosphate with zidovudine phosphoropiperidate based on the DCI activation of P-N bond afforded the desired product in good yield.

Coulometric generation of acetylions by oxidation of mercury in acetic anhydride and in acetic acid/acetic anhydride mixture

1988 ◽  
Vol 212 ◽  
pp. 73-79 ◽  
Author(s):  
V. Vajgand ◽  
R. Mihajlović ◽  
Lj. Mihajlović ◽  
V. Joksimović
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride

Sodium Perborate/Acetic Anhydride: A Convenient Reagent for the Conversion of Cyclic Acetals to Esters

Synlett ◽  
1995 ◽  
Vol 1995 (04) ◽  
pp. 329-330 ◽  
Author(s):  
Shridhar Bhat ◽  
A. R. Ramesha ◽  
S. Chandrasekaran
Keyword(s):  
Acetic Anhydride ◽  
Sodium Perborate ◽  
Cyclic Acetals

Microwave Irradiated Acetylation of p-Anisidine: A Step towards Green Chemistry

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Mousumi Chakraborty ◽  
Vaishali Umrigar ◽  
Parimal A. Parikh
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Green Chemistry ◽  
Acetic Anhydride ◽  
Microwave Irradiation ◽  
Organic Solvent ◽  
Reaction Times ◽  
Microwave Energy ◽  
Operating Parameters ◽  
Feed Composition

The present study aims at assessing the effect of microwave irradiation against thermal heat on the production of N-acetyl-p-anisidine by acetylation of p-anisidine. The acetylation of p-anisidine under microwave irradiation produces N-acetyl-p-anisidine in shorter reaction times, which offers a benefit to the laboratories as well as industries. It also eliminates the use of excess solvent. Effects of operating parameters such as reaction time, feed composition, and microwave energy and reaction temperature on selectivity to the desired product have been investigated. The results indicate as high as a 98% conversion of N-acetyl-p-anisidine can be achieved within 12-15 minutes using acetic acid. The use of acetic acid as an acetylating agent against conventionally used acetic anhydride eliminates the handling of explosive acetic anhydride and also the energy intensive distillation step for separation of acetic acid. Organic solvent like acetic anhydride are not only hazardous to the environment, they are also expensive and flammable.

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