162250-90-0Relevant academic research and scientific papers
Synthesis of Natural Compounds with Alkyl-methoxy-1,4-benzoquinone Structure
Pfeifer, Jochen,Gerlach, Hans
, p. 131 - 138 (2007/10/02)
The 1,4-benzoquinones 1-7 occurring in various plants and having interesting biological properties have been synthesized from the tetrahydropyranyl ethers 17 and 21.Reaction with n-butyllithium gave selectively the ortho-lithiated compounds.These could be alkylated with the haloalkenes 13-16 and haloalkanes to give the substituted phenols 18-20 and 22-25 in high yield after methanolysis.Alkylations of the methoxyisopropylether 8 of 10-undecyn-1-ol with bromobutane and bromohexane gave 9 and 10.These alkynols could be selectively hydrogenated with Lindlar-Palladium catalyst to give the (Z)-alkenols 11 and 12 which could be converted into the bromoalkenes 13, 14 and the iodoalkenes 15, 16.Oxidation of the phenols 18-20 and 22-25 with molecular oxygen in the presence of salcomine as catalyst produced the substituted 1,4-benzoquinones 1-3 and 26-29 in high yield.Selective hydrolysis with perchloric acid converted 26-29 into the natural products 4-7. - Key Words: Tetrahydropyranyl-ethers / ortho-Lithiation / ortho-Alkylation / 1,4-Benzoquinones, alkyl-methoxy- / 1,4-Benzoquinones, alkyl-hydroxy-methoxy-
