Two Days Before Period, Cervix High

Davidoffski and Nysted reagent

In his post on styntezy total wertyny Martin mentioned quite original chemical compound, called. Nysted reagent. Since I have personally going crazy for point of the reactants and reaction names, and due to the fact that it is an organometallic compound, I decided to take it "wallpaper" and write about it a little bit more;)

Nysted reagent (called Nysted reagent ), formally: cyclo -dibromodi- μ -methylene [ μ - (tetrahydrofuran)] tricynk , the compound having a (probable) structure:

be obtained by reaction of zinc-lead alloy in tetrahydrofuran ( THF ) With methylene bromide at 80 ^of C :

Nysted reagent is a white solid, which a suspension in THF-e (it is available commercially as a 20% solution), does not dissolve in dimethylformamide ( DMF , not to be confused with 2.5 dimetylofuranem , which is often referred to the same acronym) or 1,3-dimethyl-2-imidazolidonie ( DMI ).

DMF

DMI

metylenuje Nysted reagent carbonyl groups. For example (according to Synlett 1998 , 3, 313-15):

• methylene chiral aldehydes does not change the configuration of the center stereogenicznego
• for metylenowania ketoaldehydów selectively converted into an aldehyde group is only
• metylenowaniu ketones are in the presence of titanium chloride ( TiCl ₂ , TiCl ₃ , TiCl ₄ ) and BF ₃ × OEt ₂

_{metylenowania mechanism of the process is not yet known.}