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Organosamarium reagents Barbier-type reactions

Nitriles and esters are also unreactive in Smh-promoted Barbier reactions. A very useful procedure for lactone synthesis has been developed making use of this fact. Treatment of 7-bromobutyrates or 8-bro-movalerates with Smh in THF/HMPA in the presence of aldehydes or ketones results in generation of lactones through a Barbier-type process (equations 25 and 26). This nicely complements the -metaUo ester or homoenolate chemistry of organosamarium(III) reagents described above (Section 1.9.2.1), and also the Reformatsky-type chemistry promoted by Sml2 (Section 1.9.2.3.2). Further, it provides perhaps the most convenient route to 7- and 8-carbanionic ester equivalents yet devised. [Pg.259]

See other pages where Organosamarium reagents Barbier-type reactions is mentioned: [Pg.170]    [Pg.313]    [Pg.401]   
See also in sourсe #XX -- [ Pg.255 ]

See also in sourсe #XX -- [ Pg.255 ]

See also in sourсe #XX -- [ Pg.255 ]

See also in sourсe #XX -- [ Pg.255 ]

See also in sourсe #XX -- [ Pg.255 ]



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Barbier

Barbier-type reaction

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