A new general synthesis of 3- and 3,4-substituted 4a–q, 3,4-annelated 7a–d and condensed tricyclic 9a–e thiophenes has been developed through Simmons-Smith reaction on the respective α-oxoketene dithioacetals. Extension of the reaction to α-cinnamoylketene dithioacetals 10a–e and its higher enyl analogs 13a–d, 15a–c gave the corresponding 3-styryl 11a–e and 3-di- and trienyl 14a–d, 16a–c thiophenes
Cyclocondensation of α-oxoketene dithioacetals with β-lithioamino-β- substituted acrylonitriles:synthesis of 2,6-substituted and 5,6-annelated 3-cyano-4- (methylthio) pyridines
作者:Arun K. Gupta、Hiriyakkanavar Ila、Hiriyakkanavar Junjappa
DOI:10.1016/s0040-4020(01)81540-4
日期:1990.1
The lithiated β-amino-β-substituted acrylonitriles 4a-d generated in situ by reaction of lithioacetonitrile with either acetonitrile or substituted nitriles undergo cyclocondensation with α-oxoketenedithioacetals through 1,4-addition to afford 2,6-substituted and 5,6-annelated-4-(methylthio)-3-cyanopyridines 6a-m, 11a-h and 12a-b in good yields. A few of the 2,6-diheterylpyridines 6n-q were also synthesized
Cycloaromatization of α-oxoketene dithioacetals with 2-picolyllithium: A facile quinolizinium cation annelation
作者:Maiiakel P Balu、Hiriyakkanavar Ila、Hiriyakkanavar Junjappa
DOI:10.1016/s0040-4039(00)96275-0
日期:——
α-Oxoketenedithioacetals derived from various cyclic and acyclic ketones are shown to be useful intermediates for the synthesis of substituted and fused quinolizinium derivatives by reaction with 2-picolyllithium followed by cyclization in the presence of borontrifluoride etherate.
Regiospecific generation and application of 3-lithiomethyl-2-methyl-1-phenylpyrazolin-5-one as 1,3-binucleophile in aromatic annelation: A novel approach for synthesis of 1,2-disubstituted indazolones and their condensed analogs
作者:Kethiri R. Reddy、Amrita Roy、Hiriyakkanavar Ila、Hiriyakkanavar Junjappa
DOI:10.1016/0040-4020(95)00650-w
日期:1995.10
The enolate anion 5A generated by deprotonation of 2,3-dimelhyl- 1-phenylpyrazolin-5-one is shown to undergo highly regioselective γ-1,4-addition to α-oxoketene dithioacelals followed by cycloaromatizalion in the presence of boron trifluoride etherate to afford wide range of novel substituted and condensed indazolones in good yields.