Synthetic model of a new deoxybenzoin derivative from Deguelia hatschbachii A.M.G. Azevedo

Abstract

In this paper we describe the synthesis of 2 ́,4 ́-dimethoxy-8-(propyl-2-one)-deoxybenzoin, anew compound employed as a model for the comparison with the respective spectral data for 6’,4-dihydroxy-3’-(3,3- dimethylallyl)-2",2"-dimethylchromene(5",6":5’,4’)-2’-methoxy-8-(propyl-2-one)deoxybenzoin, recently isolated from Deguelia hatschbachii A.M.G. Azevedo. Both compounds have a“propyl-2-one” group attached to C-8 of the deoxybenzoin skeleton, for which there is no precedent inthe literature. The Friedel-Crafts reaction of 1,3-dimethoxybenzene with phenylacetyl chloride furnished2 ́,4 ́-dimethoxydeoxybenzoin, that after reaction with allyl bromide gave 2 ́,4 ́-dimethoxy-8-(allyl)-deoxybenzoin. Wacker oxidation gave the desired model compound in 15% overall yield. The correspondingspectral data reinforced the structure previously determined for the natural product.