Showing papers by "B. Mark Heron published in 1994"
TL;DR: A facile synthesis of 4-bromo-2H-chromenes and 2H-thiochromenes from the corresponding ketones and PBr3 is described in this paper.
35 citations
TL;DR: In this article, 3-Chloro-3-chlorosulfenylchroman-4-ones are efficiently obtained from chroman 4-ones by treatment with thionyl chloride.
17 citations
TL;DR: In this article, a simple four-step synthesis of a 6,6 disubstituted 6a,12a-dihydro-6H,12H-[1]benzopyrano[3,4,b]-[1]bzoprin-12-one 6 from a chroman-4-one 3 is described.
Abstract: A simple four-step synthesis of a 6,6-disubstituted 6a,12a-dihydro-6H,12H-[1]benzopyrano[3,4,-b]-[1]benzopyran-12-one 6 from a chroman-4-one 3 is described. Application of the synthetic strategy to a thiochroman-4-one leads to the 5-thiorotenoid system.
16 citations
TL;DR: Tiochroman-4-ones and chroman 4-ones react with an excess of thionyl chloride to give the α-chlorosulfenyl chlorides (2) which form sulfenamides (3) when treated with secondary amines as mentioned in this paper.
11 citations
11 citations
TL;DR: In this article, a mixture of thiochroman-3 and 4-ols is fomed which was separated only after the selective dehydration of the 4-ol. The resulting 4-methylene derivative was isolated as the hetero Diels-Alder spiro-liked adduct.
10 citations
TL;DR: Directed lithiation of chroman-4-ols occurs predominantly at C-5 under kinetic control, but at c-8 at higher temperatures as mentioned in this paper, where chroman 4-ols are converted into pyrano[4,3,2-de] phthalazines.
Abstract: Directed lithiation of chroman-4-ols occurs predominantly at C-5 under kinetic control, but at C-8 at higher temperatures. Dehydration and oxidation of the products provides viable routes to 5-substituted 2H-chromenes and chroman-4-ones, respectively. The chroman-4-ones have been converted into novel pyrano[4,3,2-de] phthalazines. 2,2,5,7-Tetramethylchroman-4-ol is preferentially lithiated at the 5-methyl group and leads to the pyrano[2,3,4-de][1]benzopyran system.
10 citations