- Fluorinative Beckmann fragmentation: Fluorinative α-cleavage of cyclic ketoximes by diethylaminosulfur trifluoride
-
Diethylaminosulfur trifluoride reacted with cyclic ketoximes bearing substituent(s) that can stabilize a carbocation to cause fluorinative fragmentation, affording fluorinated carbonitrile. Ketoximes lacking such substituents afforded complex mixtures. However, the introduction of a sulfur functionality, which can stabilize a carbocation and can be easily removed from the reaction products, into the ketoxime was effective for producing the fluorinative fragmentation.
- Kirihara, Masayuki,Niimi, Kanako,Okumura, Maiko,Momose, Takefumi
-
-
Read Online
- Propylphosphonic anhydride (T3P): A remarkably efficient reagent for the one-pot transformation of aromatic, heteroaromatic, and aliphatic aldehydes to nitriles
-
Propylphosphonic anhydride has been demonstrated to be an efficient reagent for the transformation of aromatic, heteroaromatic, and aliphatic aldehydes to respective nitriles in excellent yields. This procedure offers simple and one-pot access to nitriles and highlights the synthetic utility of T3P as a versatile reagent in organic chemistry. Georg Thieme Verlag Stuttgart - New York.
- Augustine, John Kallikat,Atta, Rajendra Nath,Ramappa, Balakrishna Kolathur,Boodappa, Chandrakantha
-
experimental part
p. 3378 - 3382
(2010/03/03)
-
- Synthesis of 2,3,4,5-tetrasubstituted pyrroles from aromatic ketoximes using the TiCl4/Et3N reagent system
-
Aryl alkyl ketoximes react with the TiCl4/Et3N reagent to give 2,3,4,5-tetrasubstituted pyrroles in moderate to good yields (55-81%).
- Periasamy, Mariappan,Srinivas, Gadthula,Seenivasaperumal, Muthu
-
p. 270 - 272
(2007/10/03)
-
- Ketone precursors for organoleptic compounds
-
The invention discloses ketones of formula I: wherein, Y is an optionally substituted alkyl, cycloalkyl, or cycloalkylalkyl, wherein each alkyl group is straight or branched and each alkyl and cycloalkyl group is saturated or unsaturated; R1is hydrogen or a C1-6alkyl group that is substituted, saturated or unsaturated, straight or branched; A is a chromophoric substituted aromatic ring or ring system; n is an integer; and with the proviso that formula I is not 2-ethoxy-1-phenyl-ethanone. These compositions are useful for the delivery of organoleptic compounds, especially of flavors, fragrances, masking agents and antimicrobial compounds.
- -
-
-
- Improved procedures for the Beckmann rearrangement: The reaction of ketoxime carbonates with boron trifluoride etherate
-
A variety of ketoxime ethyl carbonates-easily prepared from the oximes and ethyl chloroformate-undergo the Beckmann rearrangement upon treatment with 1 equivalent of boron trifluoride etherate, in dichloromethane solution at room temperature in excellent yields (generally 75-99%). (C) 2000 Elsevier Science Ltd.
- Anilkumar,Chandrasekhar, Sosale
-
p. 5427 - 5429
(2007/10/03)
-
- Pyridoannelation of Hindered Ketones via their Nitrogen Derivatives. Synthesis of 5,6,7,8-Tetrahydro-8,9,9-trimethyl-5,8-methanoquinolines from (+)-Camphor
-
The tranformation of (+)-camphor into (+)-8,9,9-trimethyl- and (+)-2,8,9,9-tetramethyl-5,6,7,8-tetrahydroquinolines 1 and 2 has been accomplished by three different procedures based on the elaboration of imino or enamino intermediates.The values of the rotatory powers for the compounds are reported.
- Chelucci, Giorgio,Delogu, Giovanna,Gladiali, Serafino,Soccolini, Francesco
-
p. 1395 - 1399
(2007/10/02)
-
- Camphor/Longicamphor and 7β-Formylnorlongifolane/7β-Acetylnorlongifolane Oximes: A Comparative Beckmann Rearrangement Study
-
Camphor oxime (3)/longicamphor oxime (4) have been shown to undergo Beckmann fragmentation on exposure to tosyl chloride in pyridine generating olefinic nitriles: 3->5+6 and 4->7+8+9; in the case of 4 this reaction provides an entry into the bicyclononane system characteristic of the secolongifolene diol fungal metabolite (10). 7β-Formylnorlongifolane oxime (14)/7β-acetylnorlongifolane oxime (15) when treated with the same Beckmann catalyst under similar conditions, afford the nitrile (16)/amide (17); on hydrolysis with base 17 gives the amine 18.Reaction of longicamphor (2) with hydroxylamine-O-sulfonic acid, however, a ffords the nitrogen-insertion product, α-longicamphidone (24) besides the fragmented nitrile (7).
- Satyanarayana, N.,Shitole, H. R.,Nayak, U. R.
-
p. 997 - 1001
(2007/10/02)
-
- INSECT GROWTH REGULATORS. PART XV. SYNTHESES OF JUVENOIDS WITH THE 2,3,3-TRIMETHYL-1-CYCLOPENTENE SYSTEM
-
New analogs of insect juvenile hormone were obtained by a multi-step synthesis starting from β-campholenenitrile (2).The Grignard reaction and the Claisen rearrangement by the orthoacetate method were applied for building and elongating an aliphatic chain.All compounds obtained are characterized by the presence of trans-disubstituted double bonds in the β-position in relation to the cyclopentane ring.
- Wawrzenczyk, Czeslaw
-
p. 135 - 147
(2007/10/02)
-