| dc.description.abstract | The methylenation of â-lactones 5 with dimethyltitanocene provides a versatile, reliable, and highly
chemoselective entry to 2-methyleneoxetanes 7. The conversion proceeds selectively in the presence
of alkenes, unprotected alcohols, and a variety of other carbonyl moieties. A study of conditions for
the optimization of this reaction is delineated. In addition, the first X-ray structure of a
2-methyleneoxetane, which shows its similarity to related â-lactones, is reported. Reactivity studies
of 2-methyleneoxetanes are presented in which it is demonstrated that these compounds are attacked
at C-4 with a nucleophile; then, subsequently, the resultant enolate reacted with an electrophile.
An interesting dichotomy of reactivity was observed when methyleneoxetane 7c was treated with
electrophiles. Reaction of 7c with acetic acid gave acetoxyoxetane 19. When 7c was exposed to
bromine, dibromoketone 20 resulted. | en |
