Dioxolane

Dioxolanes are a group of organic compounds containing the dioxolane ring. Dioxolanes can be prepared by acetalization of aldehydes and ketalization of ketones with ethylene glycol.{{OrgSynth : (+)-cis-Dioxolane is the trivial name for which is a muscarinic acetylcholine receptor agonist. ==Protecting groups==

Organic compounds containing carbonyl groups sometimes need protection so that they do not undergo reactions during transformations of other functional groups that may be present. A variety of approaches to protection and deprotection of carbonyls are known. For example, consider the compound methyl cyclohexanone-4-carboxylate, where lithium aluminium hydride reduction will produce 4-hydroxymethylcyclohexanol. The ester functional group can be reduced without affecting the ketone by protecting the ketone as a ketal. The ketal is produced by acid catalysed reaction with ethylene glycol, the reduction reaction carried out, and the protecting group removed by hydrolysis to produce 4-hydroxymethylcyclohexanone. NaBArF4 can also be used for deprotection of acetal or ketal-protected carbonyl compounds. ::PhCH(OCH2)2   +   H2O   ->[\ce{NaBAr4}][\text{30 °C / 5 min}] PhCHO + HOCH2CH2OH ==Natural products==

Neosporol is a natural product that includes a 1,3-dioxolane moiety, and is an isomer of sporol which has a 1,3-dioxane ring. The total synthesis of both compounds has been reported, and each includes a step in which a dioxolane system is formed using trifluoroperacetic acid (TFPAA), prepared by the hydrogen peroxide – urea method. This method involves no water, so it gives a completely anhydrous peracid, necessary in this case as the presence of water would lead to unwanted side reactions. with trifluoroperacetic acid is used to convert a suitable allyl alcohol precursor to an epoxide, which then undergoes a ring-expansion reaction with a proximate carbonyl functional group to form the dioxolane ring. A similar approach is used in the total synthesis of sporol, with the dioxolane ring later expanded to a dioxane system. ==See also==