(6S,7R)-6-(hydroxymethyl)-6-methyl-2,4-dioxido-2,4-dioxo-1,3,5-trioxa-2$l^{5},4$l^{5}-diphosphacyclooctan-7-ol
(6S,7R)-2,4-diketo-6-methyl-6-methylol-2,4-dioxido-1,3,5-trioxa-2$l^{5},4$l^{5}-diphosphacyclooctan-7-ol