Cycloaromatization of α-oxoketene dithioacetals and β-oxodithioacetals with benzyl-,1-(naphthylmethyl) and 2-(naphthylmethyl)magnesium halides: Synthesis of condensed polynuclear aromatic hydrocarbons
作者:Ch.Srinivasa Rao、Maliakel P Balu、Hiriyakkanavar Ila、Hiriyakkanavar Junjappa
DOI:10.1016/s0040-4020(01)86411-5
日期:1991.1
An efficient route for the synthesis of substituted naphthalenes, phenanthrenes and other polynuclear aromatic hydrocarbons has been developed. The methodology involves 1,2- (or sequential 1,4- and 1,2-) addition of either benzyl, 1-(naphthylmethyl) or 2-(naphthylmethyl) magnesium halides to α-oxoketenedithioacetals or β-oxodithioacetals followed by borontrifluoride etherate catalyzed cycloaromatization
Regioselective synthesis of substituted 1-methyl- and 2-methylnaphthalenes
作者:K Mallik Yadav、Pramod K Mohanta、Hiriyakkanavar Ila、Hiriyakkanavar Junjappa
DOI:10.1016/0040-4020(96)80832-5
日期:1996.10
Regiospecificallysubstituted 1-methyl- and 2-methylnaphthalenes, 5-methyl- and 6-methyl-1,2,3,4-tetrahydroanthracenes have been synthesized in good yields through 1,2- addition of the corresponding α-lithio-o-or m-xylenes onto α-oxoketenedithioacetals or their dihydro derivatives followed by cyclodehydration of the resulting carbinols in the presence of borontrifluoride etherate.
The reactions of enamines with sulfoxides bearing α-hydrogens in the presence of a magnesium amide, generated in situ from the reaction of ethylmagnesium bromide with diisopropylamine, afforded the corresponding α-sulfenylalkylated ketones and aldehydes in isolated yields ranging from 39 to 76%. This procedure was successfully extended to the bis(methylthio)methylation with methyl (methylthio)methyl
Highly regioselective 1,2-addition of alkoxybenzyl Grignard reagents to α-oxoketene dithioacetals: A facile regiocontrolled synthesis of alkoxynaphthalenes and their condensed analogs via aromatic annelation
作者:Barun K Mehta、Sukumar Nandi、H Ila、H Junjappa
DOI:10.1016/s0040-4020(99)00757-7
日期:1999.10
4-Methoxybenzyl- (A), 3,4-dimethoxybenzyl- (B) and 3,4-methylenedioxybenzyl- (C) Grignard reagents are shown to undergo regioselective 1,2-addition with various acyclic and cyclic α-oxoketene dithioacetals to afford carbinol dithioacetals which on BF3.Et2O catalyzed cyclization yield alkoxynaphthalenes and their condensed derivatives in a highly regiocontrolled manner.