A Modified Synthesis of 3,4 Dihydro-2,2 Dimethyl-2H-1 Benzopyran-6- Butyric Acid (DBA), A Possible Antisickling Agent
McCue, Michael G.
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DBA,3,, 4 dihydro-2, 2 dimethyl-2H-l benzopyran-6-butyric acid, was successfully synthesized with an overall yield of 20%. The.synthesis as presented by Ekong et al (1) could not be duplicated. The synthesis as presented here required a modification of the Friedal Crafts acylation reaction. An acid chloride, methyl-4-chloro-4-oxubutanote, was used instead of succinic anhydride. The synthesis consisted of a methyl Grignard addition to dihydrocoumarin followed by an acid catalyzed dehydration to yield 3. 4-dihydro-2, 2- dimetyl-2H-1-benzopyran (2, 2 dimethylchroman). The Friedal Crafts acylation of 3, 4-dihydro-2, 2~diJnethyl-2H-1 benzopezran was then performed and a modified Clemmensen reduction of 3, 4 dihydro-2, 2 dimethyl-T-oxo-2H-l benzopyran-6-butanoic acid completed the synthesis.