(2R3R)-14-Dioxa­spiro­4.4nonane-23-di­carb­oxy­lic and (2R3R)-14-dioxa­spiro­4.5decane-23-di­carb­oxy­lic acids

摘要

The title compounds, C9H12O6 and C10H14O6, were formed by careful hydrolysis of the corresponding diethyl esters. Their single crystals were grown from an ethyl acetate/hexane mixture. Crystals of both compounds have monoclinic (P21) symmetry with a single mol­ecule in the asymmetric unit. Both crystal structures are very similar and display four –CO—OH⋯O=C(OH)– hydrogen bonds, forming a two-dimensional double-layered framework.