Dioxepanes, hydrolysis

Lactic acid and 3-(2-hydroxyethoxy)-propanoic acid (HPA) were the main hydrolysis products of l-LA, dl-LA and l,5-dioxepan-2-one (DXO) copoly-... 

Treatment of 2,2-dimethyl-1,3-dioxepane with carboxylic acids results in the formation of tetra-hydrofuran and acetone <6UOC4762>. Acid-catalyzed hydrolysis of methyl-substituted 2,2-diphenyl-... 

The parent member of this class of compounds, l,4-dioxepan-5-one, and its methyl derivatives (119) have been prepared by Baeyer-Villiger oxidation, and the methyl derivative has been transformed to the dioxepinone (121) <89MM3838,94CC687>. l,4-Dioxepan-5-one could also be obtained by cyclization of (122) and hydrolysis of the intermediate iminoether hydrochloride (123) (Scheme 11) <89MM3838>. 

Arynes have also been employed in a variety of [2+2] cycloadditions. By employing Stevens s and Bisacchi s methodology for the synthesis of benzocydobutenones [94], Santelli et al. have examined the synthesis of benzo-biscyclobutenone 173 by the [2+2] cydoaddition of a dibenzyne with 2-methylene-l,3-dioxepane (Scheme 12.50) [95]. The biscycloadduct 172 was obtained in a 20% yield and smoothly transformed to the corresponding bisketone 173 after hydrolysis. The stracture of 172 was confirmed by single-crystal X-ray analysis. 

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