Novel ring-expansion reaction between formaldehyde cyclic acetal and ethylene oxide

We formerly found the novel ring-expansion reaction between 1,3,5-trioxane and ethylene oxide, and identified three novel compounds. Now, we found thi s type of reaction can be generalized to the ring-expansion reaction betwee n formaldehyde cyclic acetal and ethylene oxide. We, first, confirmed this type of reaction between 1,3-dioxolane and ethylene oxide to form 1,3,6-tri oxacyclooctane, 1,3,6,9-tetraoxacycloundecane and 1,3,6,9,12-pentaxacyclote tradecane. When the initial ethylene oxide concentration is low, the format ion of 1,3,6-trioxacyclooctane is predominant and selectivity for the forma tion of 1,3,6-trioxacyclooctane is nearly 99%. However, with the increase i n initial ethylene oxide concentration, the formation of mixed reaction pro ducts of 1,3,6-trioxacyclooctane, 1,3,6,9-tetraoxacycloundecane and 1,3,6,9 ,12-pentaoxacyclotetradecane was observed. Further we confirmed the similar type of ring-expansion reaction between 1,3-dioxacycloheptane and ethylene oxide. From these observations, we concluded the general ring-expansion re action between formaldehyde cyclic acetal and ethyelne oxide is valid.