Method of acylation of phloroglucinol
AssigneeAtlantic Research Institute Limited
InventorsWolfgang Reininger, Alfons Hartl
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Abstract
A method of acylation of phloroglucinol in the presence of a Friedel Crafts catalyst which is effected in the presence of nitromethane and dichloromethane so as to produce an acylphloroglucinol. The acylphloroglucinol is reacted with a compound selected from .gamma.,.gamma.-dimethyl allyl bromide and 2-methyl-but-3-ene-2-ol in the presence of a weak Lewis acid and in an organic solvent to produce a 4-desoxyhumulone which is then oxidized to produce a corresponding humulone.
Claims23
In a method of producing an acylphloroglucinol for use in the preparation of humulone comprising acylation of phloroglucinol in the presence of a Friedel Crafts catalyst so as to produce said acylphloroglucinol, the improvement comprising carrying out said acylation in the presence of at least 1.5 moles of nitromethane per mole of phloroglucinol and in dichloromethane as solvent.
In a method of producing a 4 - desoxyhumulone for use in the preparation of a humulone comprising alkylation by reacting an acylphloroglucinol with a compound selected from the group consisting of .gamma., .gamma.-dimethylallyl bromide and 2 - methyl - but - 3 -ene - 2 - ol so as to produce said 4 -desoxyhumulone, the improvement comprising carrying out said alkylation reaction in an organic solvent selected from the group consisting of dioxane, methylene chloride and ether/methylene chloride, in the presence of a weak Lewis acid catalyst selected from the group consisting of ZnCl.sub.2, POCl.sub.3 and acid ion exchanger.
Dependencies are inferred from the claim text.