Dihydroacetic acid

Head-to-tail dimers result from the photolysis of dihydroacetic acid, a food additive, in the solid phase(131> ... 

For example, treatment of l-(2-hydroxyphenyl)-3-arylpropenones 9 with o-PDA 1 carried out in dimethyl sulfoxide in the presence of sodium acetate under microwave irradiation produces dihydrodiazepines 10 in good yields [10] (Scheme 4.3). Chalcone analogues of dihydroacetic acid 11, as well, containing an 6>r /z0-hydroxyl group, react with 0-PDA in boiling ethanol to produce dihydrobenzodiazepines 12 [11, 12]. 

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