454 2-oxetanone, applications

Practical applications of oxetanes and 2-oxetanones are numerous, as evidenced by the thousands of patents that have been issued in this area. Space permits mention of only a few of what seem major applications. 

Very litde is known about the toxicology of other dimeric ketenes. For the dimeric dimethylketene there is equivocal evidence of tumors resulting from massive exposure in rats reported for the (3-lactone form (3,3-dimethyl-4-isopropylidene-2-oxetanone), whereas the symmetric form (2,2,4,4 tetramethylcyclobutane-l,3-dione) induces tumors in mice after lengthy skin applications. 

In an interesting application of Lewis acid-mediated oxirane ring openings, diazomethyl-chlorohydrins, formed from a,/ -epoxy diazomethylketones with SnCl4, cyclize to 3-oxetanones (Scheme 15) <92T9985>. 

As already mentioned, applications of the Mitsunobu reaction in lactone formation are significantly less common. Like so many other applications of the Mitsunobu reaction, the application of the Mitsunobu reaction for the preparation of lactones was first reported by Mitsunobu s group.Later on, Mitsunobu s group used the reaction to prepare colletodiol. Since then the scope of the reaction has been expanded to include the well known application of the Mitsunobu reaction for the preparation of amine protected (5)-3-amino-2-oxetanones derived from the correspondingly protected serine precursor this protocol was initially discovered by Vederas and... 

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