G. Anilkumar

Diels-alder reactions of o-benzoquinones with 6-substituted fulvenes: Facile synthesis of 1-aryl and 1,1-diarylmethylene-4,7-ethanoindene-8,9-diones 1

Abstract 3,5-Di- tert -butyl-, 4- tert -butyl- and 3-methoxy- o -benzoquinones have been shown to undergo facile thermal cycloaddition to symmetrical and unsymmetrical fulvenes to give bicyclo[2.2.2]octene diones in high yields.

[4+2] Cycloaddition reactions of coumarin quinone methide with pentafulvenes: facile synthesis of novel polycyclic pyran derivatives

Abstract The quinone methide generated in situ by the Knoevenagel condensation of formaldehyde and 4-hydroxycoumarin underwent facile Diels–Alder reactions with pentafulvenes to afford novel pyranocoumarin derivatives in good yields.

Cycloaddition reactions of 3-ethoxycarbonyl-2H-cyclohepta[b]furan-2-one with 6,6-dialkyl, cycloalkyl and diaryl pentafulvenes

Abstract Competing [8 + 2] and [4 + 2] modes of additin of 3-ethoxycarbonyl-2H-cyclohepta[b]furan-2-one with dialkyl, cycloalky and diaryl pentafulvenes are described.

Photolytic double decarbonylation route to highly substituted indenes and benzene derivatives

Abstract UV irradiation of cyclohexane solution of a 4,7-ethanoindene-8,9-dione derivative led to a facile extrusion of two molecules of carbon monoxide to give a dihydroindene along with its dehydrogenated product, a methylene indene (benzofulvene). The inseparable mixture of dihydroindene and benzofulvene on treatment with DDQ underwent dehydrogenation and equilibration to afford the latter as a single stereoisomer in high yield. The double CO extrusion process is a general reaction and it has been applied to the synthesis of a number of benzofulvenes and highly substituted benzene derivatives.

DIELS-ALDER REACTIONS OF A 6-ARENYL FULVENE WITH DIENES AND DIENOPHILES AND RELATED CHEMISTRY

Abstract 6-(2-Phenyl ethenyl) fulvene has been shown to participate both as diene and dienophile in Diels-Alder reactions and a facile photochemical transformation of the resulting bicyclo[2.2.2]-octenediones leading to extensively conjugated benzofulvenes has been accomplished.

[8+2] Cycloaddition Reactions of 2H-Cyclohepta[b]furan-2-one with Acyclic 1,3-Dienes: A Facile Route to Novel Bicyclo [5.3.0] ring Systems

Abstract Novel [8+2] cycloaddition reactions of 3-ethoxy carbonyl 2H-cyclohepta[b]furan-2-one with acyclic 1,3-dienes are described. The potential application of this process in the synthesis of modified colchicinoids incorporating bicyclo [5.3.0] ring systems has also been studied.

Borontrifluoride-etherate induced rearrangement of bicyclo[2.2.2]octene-7,8-diones: An efficient synthesis of bicyclo[3.2.1]octene-2,8-diones

Abstract A facile conversion of bicyclo[2.2.2]octene-7,8-diones to bicyclo[3.2.1]octene-2,8-diones mediated by BF3-etherate in chloroform is described.

Photochemical di-π-methane rearrangement of quinoxalinobarrelenes

Quinoxalinobarrelene 1 underwent facile di-π-methane rearrangement when irradiated in cyclohexane at 250 nm to afford quinoxalinose-mibullvalene 2 in 94% yield. Similar rearrangement was observed with 3 leading to the corresponding semibullvalene 4.

Cycloaddition reactions of 2-oxo-2H-cyclohepta[b]furan derivatives with dienes and dienophiles

Abstract Cycloaddition reactions of 2-oxo-2H-cyclohepta[b]furan derivatives participating as 8π and 4π components respectively towards different dienes and dienophiles are described. The observed reactivity and periselectivity have been rationalized by AM1 calculations.

ZnCl2 Catalysed Diels-Alder Reactions of Oxa and Aza Bicyclo[3.2.1]systems with Dienes: Formation of Some Novel Heterocyclic Systems

ZnCl2 catalysed Diels-Alder reactions of oxa and aza bicyclo[3.2.1systems with dienes yielding highly functionalized heterocycles are described.