Organocerium reagents synthesis

Organocerium reagents also show excellent reactivity toward nitriles and imines,205 and organocerium compounds were found to be the preferred organometallic reagent for addition to hydrazones in an enantioselective synthesis of amines.206... 

A similar but bulkier organocerium reagent 26 was applied to the total synthesis of bilosespenes A and B.1S Upon reaction of 26 and ketone 25, the target intermediate 27 was obtained in 76% yield as a single isomer (Scheme 9). 

Attempts to extend these reactions to the synthesis of simple hydroxylamines were plagued by deprotonation and redox side-reactions, but recently yields have been much improved by conversion of the Grignard reagent into an organocerium reagent in situ [12] for example, yV-butyl-A-propylhydroxylamine was prepared in 90% yield. Another successful variant utilized A-nitrosodiphenylamine to generate a nitroso compound in situ. The hydroxylamine salt produced was oxidized in situ to give a nitroxide [13] ... 

Recently, Mudryk and Cohen have found that reactions of lactones with organocerium reagents provide lactols in go yields, as exemplified in Scheme 10. This reactiim leads to an efficient (xie-pot synthesis of spiroketais, as illustrated in Scheme 11. ... 

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