Showing papers by "Kalpattu K. Balasubramanian published in 1994"
TL;DR: In this article, aryl allenylmethyl ethers with tris(4-bromophenyl)aminium hexachloroantimonate in acetonitrile at room temperature were treated with a facile cation radical induced Claisen rearrangement to yield 2-(o-hydroxyaryl)buta-1,3-dienes.
Abstract: Treatment of aryl allenylmethyl ethers with tris(4-bromophenyl)aminium hexachloroantimonate in acetonitrile at room temperature induces a facile cation radical induced Claisen rearrangement to yield 2-(o-hydroxyaryl)buta-1,3-dienes.
9 citations
TL;DR: In this paper, a ring-opening reaction yielding o-allenylphenyl acetates is described, which is a ring opening reaction of 3-bromochromenes.
Abstract: Cathodic reduction of 3-bromochromenes led to a ring-opening reaction yielding o-allenylphenyl acetates.
8 citations
TL;DR: Wieland-Miescher ketone analogues are prepared by monoalkylation of cyclohexane-1,3-dione with bromomethylcycloalkenyl bromides followed by annulation with methyl vinyl ketone; they undergo 5-exo-trig competitive intramolecular radical addition to the keto and enone olefins to give angularly rused carbocycles and propellanes, respectively as discussed by the authors.
Abstract: Wieland–Miescher ketone analogues are prepared by monoalkylation of cyclohexane-1,3-dione with bromomethylcycloalkenyl bromides followed by annulation with methyl vinyl ketone; they undergo 5-exo-trig competitive intramolecular radical addition to the keto and enone olefins to give angularly rused carbocycles and propellanes, respectively.
8 citations
TL;DR: In this article, the oxidation reactions of aromatic 3,3-sigmatropic systems have been investigated under different conditions viz, (a) anodic oxidation in amphipr
5 citations
TL;DR: In this paper, a remarkable difference in chemoselectivity was noticed in reductive cyclisation of cycloalkenyl bromides, resulting in the remote generation of the bromocyclopentenyl-methyl radical by a homolytic CC bond cleavage.
5 citations
TL;DR: In this paper, a 5-exo-trig free radical cyclisation was used to give the respective 3-ethenyl-2,3-dihydrobenzofurans and 3.
Abstract: o-Haloaryl allenylmethyl ethers and amines upon treatment with n-Bu3SnH and AIBN in refluxing benzene, underwent a 5-exo-trig free radical cyclisation to give the respective 3-ethenyl-2,3-dihydrobenzofurans and 3-ethenyl-2,3-dihydroindoles in good yields.
4 citations
TL;DR: In this article, a facile ring cleavage reaction yielding 2(α-alkoxy-allyl)phenols which are not easily accessible is described, leading to the development of a new class of 4-alkox-3-bromochromans.
2 citations
TL;DR: In this paper, the oxidation reactions of aromatic 3,3-sigmatropic systems have been investigated under different conditions viz., (a) anodic oxidation in amphipr
Abstract: The oxidation reactions of aromatic 3,3-sigmatropic systems have been investigated under different conditions viz. , (a) anodic oxidation in amphipr
TL;DR: In this article, a remarkable difference in chemoselectivity was noticed in reductive cyclisation of cycloalkenyl bromides, resulting in the remote generation of the bromocyclopentenyl-methyl radical by a homolytic CC bond cleavage.
Abstract: The behaviour of tri-n-butyltin hydride in poly functional molecule like Wieland-Miescher ketones, was found to be very unusual, a remarkable difference in chemoselectivity was noticed in the reductive cyclisation of cycloalkenyl bromides, resulting in the remote generation of the bromocyclopentenyl-methyl radical by a homolytic CC bond cleavage.
TL;DR: In this article, the synthesis of 3,4,8,8a-tetrahydro-8a(2-bromo-1-cyclo-alkenylmethyl)-1,6(2H,7H)-naphthalene-diones is reported.
Abstract: The synthesis of the hitherto unknown 3,4,8,8a-tetrahydro-8a(2-bromo-1-cyclo-alkenylmethyl)-1,6(2H,7H)-naphthalene-diones are reported.
TL;DR: A simple procedure for the C-alkylation of cyclic 1,3-diketones has been reported using Triton B as base in aqueous conditions.
Abstract: A simple procedure for the C-alkylation of cyclic 1,3-diketones have been reported using Triton B as base in aqueous conditions.
TL;DR: In this paper, aryl allenylmethyl ethers with tris(4-bromophenyl)aminium hexachloroantimonate in acetonitrile at room temperature were treated with a facile cation radical induced Claisen rearrangement to yield 2-(o-hydroxyaryl)buta-1,3-dienes.
Abstract: Treatment of aryl allenylmethyl ethers with tris(4-bromophenyl)aminium hexachloroantimonate in acetonitrile at room temperature induces a facile cation radical induced Claisen rearrangement to yield 2-(o-hydroxyaryl)buta-1,3-dienes.
TL;DR: In this paper, a facile ring cleavage reaction yielding 2(α-alkoxy-allyl)phenols which are not easily accessible is described, leading to the development of a new class of 4-alkox-3-bromochromans.
Abstract: Electrochemical reduction of 4-alkoxy-3-bromochromans in acetonitrile led to a facile ring cleavage reaction yielding 2(α-alkoxy- allyl)phenols which are not easily accessible.
TL;DR: Wieland-Miescher ketone analogues are prepared by monoalkylation of cyclohexane-1,3-dione with bromomethylcycloalkenyl bromides followed by annulation with methyl vinyl ketone; they undergo 5-exo-trig competitive intramolecular radical addition to the keto and enone olefins to give angularly rused carbocycles and propellanes, respectively as mentioned in this paper.
Abstract: Wieland–Miescher ketone analogues are prepared by monoalkylation of cyclohexane-1,3-dione with bromomethylcycloalkenyl bromides followed by annulation with methyl vinyl ketone; they undergo 5-exo-trig competitive intramolecular radical addition to the keto and enone olefins to give angularly rused carbocycles and propellanes, respectively.
TL;DR: In this article, a ring-opening reaction yielding o-allenylphenyl acetates is described, which is a ring opening reaction of 3-bromochromenes.
Abstract: Cathodic reduction of 3-bromochromenes led to a ring-opening reaction yielding o-allenylphenyl acetates.