Iron pentacarbonyl epoxides

Sodium (cyclopentadienyl)dicarbonylferrate, dicobaltoctacarbonyl, and iron pentacarbonyl have been reported to deoxygenate epoxides efficiently to the corresponding alkenes. The reaction with (cyclopentadienyl)dicarbonylfeirate proceeds with inversion of stereochemistry, whereas Fe(CO)5 shows low stereoselectivity. Both Co2(CO)8 and Fe(CO)s are applicable to epoxides having carbonyl groups (equations 45 and 46). 

Reaction with vinyl oxiranes. a, 3-Unsaturated epoxides, for example (1), on irradiation in the presence of iron pentacarbonyl give lactones such as (2). When warmed, (2) loses CO and is converted into the Fe(CO)3 complex of the... 

Dienes, after regiospecific epoxidation, react readily with pentacarbonyl iron to afford tricarbonyliron lactone complexes. These complexes can then be smoothly oxidized by ceric ammonium nitrate to give predominantly alkenyl-substituted /8-propiolactones (Scheme 36). The stereochemical integrity of the initial complexes is reflected in the structures of the oxidation products. 

---