Navigation

0 Hits

  • Previous / Next

You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via
20.5.15.1.1.7.2 Variation 2: Using a Reformatsky Reagent and a Nitrile

DOI: 10.1055/sos-SD-020-01264

Beignet, J.Science of Synthesis, (2007201352.

The addition of a Reformatsky reagent to a nitrile, known as the Blaise reaction, produces β-oxo esters in good yields when the product is mono- or disubstituted at the α-position.[‌24‌] The reaction can be carried out with modest efficiency using ethyl bromoacetate as a starting material, which when gradually added to a mixture containing a nitrile, zinc, and mercury(II) chloride in refluxing benzene generates an organometallic nucleophile. This nucleophile reacts immediately with the nitrile (always present in excess to avoid self-condensation). In the workup procedure, hydrolysis of the iminometallic intermediate 37 that is formed then produces aliphatic 3-oxo esters 38 in moderate yields (Scheme 16). The efficiency of the Blaise reaction is partially limited by the occasional formation of nitrogen-containing impurities; for example, the zinc intermediate 37 may undergo partial hydrolysis to the moderately stable enamine 39, or it can react further acting as a nucleophile with the nitrile.

Meeeee 88 Meeeeeeee ee 8-Mee Meeeee Meeee eee Meeeee Meeeeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

Meeee 8-Meeeeeeeeeee (88, M8=Me); Meeeeee Meeeeeeee:[‌88‌]

MMMMMMM: Meeeeee(MM) eeeeeeee ee e eeeeee ee eeeeeeeee eee ee eeeee ee eeee eeeeeee. Meee eeeeee ee eeeeeeeeeeeee ee eeeee eeeee eeeee ee eeeeeee.

Meeee eeeeeeeeeeee (8.8eee) ee eeeeeee (88eM) (MMMMMMM: eeeeeeeeee) eee eeeee eeeeeeee eeee 8.8e ee e eeee ee MeMM (8.88eee), Me (8.88 eeee), eee MeMe8 (eeeeee) ee eeeeeeeee eeeeeee. Meee eee eeeeeeee eee eeeeeeee, eee eeeeeee eee eeeeeeee eee e eeeeeee 8e, eeee eeeeee ee ee, eee eeeeeeeeee eeee 88% M8MM8 (888eM). Mee eeeeeeeeeeeee eeeeeee eee eeeeeee eee 8e. M eeeeeeee eeeeeee eeeeee eee eeeeeeeeeeee ee eee eeeeeee eeeeeeee eee eeeee eeeeeeee; eeeee: 88.8e (88%).

References


Cookie-Einstellungen