The title compound (8) which is an intermediate towards the isochroman system, possibly related to the fungal metabolites of rotiorin type has been synthesised. Reaction of 3,5-dibenzyloxy-4-methylphenylacetyl chloride (I) with isobutyl magnesium bromide furnished 1-{3,5-dibenzyloxy-4methyl phenyl )-4-methylpentan-2-one (2) which was debenzylated to 1-{3,5dihydroxy-4-methylphenyl)-4-methylpentan-2-one (3). Formylation of the ketone (3) gave benzopyrillium salt (6) which was decomposed to 1-{2-formyl-3,5di hydroxy-4-methyl phenyl )-4-methylpentan-2-one (7) and on methylation gave 1-{2-formyl-3,5-dimethoxy-4-methylphenyl)-4-methylpentan-2-one (8). {~)-I(3,5-Diacetoxy-4-methylphenyl)-4-methylpentan-2-ylacetate (5) was obtained from (~)-I-{3,5-dihydroxy-4-methylphenyl )-4-methylpentan-2-ol (4) which was synthesised from the ketone (3).
E S TURNER ,N H RAMA ,
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