Formation of 2,2-disubstituted 1,3-cyclopentanediones from ketals with 1,2-bis(trimethylsilyloxy)cyclobutene

1993 ◽  
Vol 71 (9) ◽  
pp. 1311-1318 ◽  
Author(s):  
Yong-Jin Wu ◽  
Dean W. Strickland ◽  
Tracy J. Jenkins ◽  
Pei-Ying Liu ◽  
D. Jean Burnell
Keyword(s):  
Double Bond ◽  
Carbonyl Group ◽  
Lewis Acid ◽  
Steric Hindrance ◽  
Catalysed Reaction ◽  
Carbon Double Bond ◽  
Direct Formation

The direct formation of 2,2-disubstituted 1,3-cyclopentanedione compounds by a Lewis acid catalysed reaction with 1,2-bis(trimethylsilyloxy)cyclobutene proceeds in good to excellent yields with unhindered ketals, but steric hindrance reduces the yields considerably. A carbonyl group α or β to the ketal, or a carbon–carbon double bond α to the ketal, stops the reaction completely. Orthoesters do not give geminally acylated products in synthetically useful yields.

Carbon-carbon double bond cleavage with a hard lewis acid and ethanethiol

1981 ◽  
Vol 22 (9) ◽  
pp. 875-878 ◽  
Author(s):  
Kaoru Fuji ◽  
Takeo Kawabata ◽  
Manabu Node ◽  
Eiich Fujita
Keyword(s):  
Double Bond ◽  
Lewis Acid ◽  
Bond Cleavage ◽  
Carbon Double Bond

Lewis Acid Promoted Carbon−Carbon Double-Bond Formation via Organozinc Reagents and Carbonyl Compounds

2009 ◽  
Vol 74 (17) ◽  
pp. 6855-6858 ◽  
Author(s):  
Zhi-Yong Peng ◽  
Fang-Fang Ma ◽  
Lv-Feng Zhu ◽  
Xiao-Min Xie ◽  
Zhaoguo Zhang
Keyword(s):  
Double Bond ◽  
Lewis Acid ◽  
Carbonyl Compounds ◽  
Bond Formation ◽  
Carbon Double Bond ◽  
Organozinc Reagents

ChemInform Abstract: Lewis Acid Promoted Carbon—Carbon Double-Bond Formation via Organozinc Reagents and Carbonyl Compounds.

ChemInform ◽  
2010 ◽  
Vol 41 (3) ◽  
Author(s):  
Zhi-Yong Peng ◽  
Fang-Fang Ma ◽  
Lv-Feng Zhu ◽  
Xiao-Min Xie ◽  
Zhaoguo Zhang
Keyword(s):  
Double Bond ◽  
Lewis Acid ◽  
Carbonyl Compounds ◽  
Bond Formation ◽  
Carbon Double Bond ◽  
Organozinc Reagents

scholarly journals Synthesis of a sucrose dimer with enone tether; a study on its functionalization

2014 ◽  
Vol 10 ◽  
pp. 1246-1254 ◽  
Author(s):  
Zbigniew Pakulski ◽  
Norbert Gajda ◽  
Magdalena Jawiczuk ◽  
Jadwiga Frelek ◽  
Piotr Cmoch ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Double Bond ◽  
Carbonyl Group ◽  
Osmium Tetroxide ◽  
Cd Spectroscopy ◽  
Allylic Alcohol ◽  
Circular Dichroïsm

The reaction of appropriately functionalized sucrose phosphonate with sucrose aldehyde afforded a dimer composed of two sucrose units connected via their C6-positions (‘the glucose ends’). The carbonyl group in this product (enone) was stereoselectively reduced with zinc borohydride and the double bond (after protection of the allylic alcohol formed after reduction) was oxidized with osmium tetroxide to a diol. Absolute configurations of the allylic alcohol as well as the diol were determined by circular dichroism (CD) spectroscopy using the in situ dimolybdenum methodology.

Reactions of 4-Pyrones with Azomethine Ylides as a Chemo­selective Method for the Construction of Multisubstituted Pyrano[2,3-c]pyrrolidines

Synthesis ◽  
2021 ◽  
Author(s):  
Dmitrii L. Obydennov ◽  
Vyacheslav D. Steben’kov ◽  
Konstantin L. Obydennov ◽  
Sergey A. Usachev ◽  
Vladimir S. Moshkin ◽  
...  
Keyword(s):  
Double Bond ◽  
Ring Opening ◽  
Azomethine Ylides ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Computational Studies ◽  
Carbon Double Bond ◽  
Reactivity Indexes ◽  
Reaction Proceeds

Abstract4-Pyrones bearing electron-donating and electron-withdrawing groups react with nonstabilized azomethine ylides to form pyrano[2,3-c]pyrrolidines in moderate to good yields. The reaction proceeds chemoselectively as a 1,3-dipolar cycloaddition of the azomethine ylide at the carbon–carbon double bond of the pyrone activated by the electron-withdrawing substituent. The reactivity of 4-pyrones toward azomethine ylides was rationalized by computational studies with the use of reactivity indexes. The pyrano[2,3-c]pyrrolidine moiety could be modified, for example by a ring-opening transformation under the action of hydrazine to provide pyrazolyl-substituted pyrrolidines.

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