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Methylenation of a-hydroxy ketone

Not only a zinc-copper couple, but also a zinc-lead couple forms a gem-dimetal species from diiodomethane, according to the 1975 Nysted patent5. He also insisted that treatment of dibromethane with a zinc-lead couple in THF at 80 °C forms a characteristic gem-dizinc species 1 (equation 3). However, there was no further evidence concerning the structure except H NMR data, which was not enough for the complete structural determination. The obtained compound was definitely a gem-dizinc species, but the written structure 1 was not fully characterized. The white solid 1 is obtained as a dispersion in THF, and does not dissolve in DMF and DMI (l,3-dimethyl-2-imidazolidinone). This THF dispersion is commercially available from Aldrich Co. as Nysted reagent. Nysted also showed that this dizinc compound is effective for the methylenation of a-hydroxy ketone moiety in steroid derivatives5. [Pg.643]

Scheme 8.2 Methylenation of a-hydroxy ketone with CH2l2-Zn(Cu) in THF. Scheme 8.2 Methylenation of a-hydroxy ketone with CH2l2-Zn(Cu) in THF.

See also in sourсe #XX -- [ Pg.349 ]




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A-Methylene ketones

A-methylenation

Hydroxy ketones

Hydroxy methylenes

Ketones methylenation

Methylenated ketones

Methylene ketones

Of methylene

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