Lactones cerium ammonium nitrate

The important anthraquinone-intermediate 810 has been synthesized in two steps from the lactone 807, which has also been used by Snider et al. for then-synthesis. With LiHMDS and cyclohex-2-enone (808), the tricyclic 809 was formed (see Scheme 12.4 (553)). Oxidation with cerium ammonium nitrate gave the anthraquinone 810. 

A recently described method for insertion of a carbon monoxide molecule into the monoepoxide of a conjugated diene gives /3-lactones in high yield. This is achieved by reaction of iron pentacarbonyl with the starting vinyloxirane to give the 7r-allyl iron complex (66), which on oxidation with cerium(IV) ammonium nitrate gives the /3-lactone. In some cases, y-Iactone products can also be obtained from this reaction (8lJCS(Pi)270). 

Cyclic ethers are oxidized to lactones in the presence of cerium(IV) salts. Treatment of tetrahydiofu-ran with cerium(rV) ammonium nitrate in the presence of primary, secondary or tertiary alcdiols leads to the formation of the corresponding tetrahydrofuranyl ethers in quantitative yield. Fuitfaermoie, 4-meth-oxybenzyl ether derivatives of carbohytbates are selectively deprotected to the parent alcohols on reaction with cerium(IV) ammonium nitrate in aqueous acetonitrile. ... 

Furthermore, ketene dithioacetals 83 prepared from unsaturated ketones 82 by means of Peterson reactions are converted to the bicydic lactones 84 by treatment with cerium(IV) ammonium nitrate (CAN) in wet acetonitrile (Scheme 2.51) [142]. The oxidative cydization occurs stereosdectively in moderate yields. 

Demetalation of ferralactone complexes with Cerium(IV) Ammonium Nitrate produces p-lactones (at low temperature) and/or 8-lactones (at high temperature, under a high pressure of carbon monoxide). 

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