87173-82-8Relevant academic research and scientific papers
SYNTHESES OF α,β-UNSATURATED KETONES STARTING FROM VINYLIC AND ALLYLIC GRIGNARD REAGENTS VIA 2-IMIDAZOLYLMETHANOL INTERMEDIATES
Hayakawa, Satoshi,Michiue, Tohru,Okamoto, Masao,Hatakeyama, Shoko,Ohta, Shunsaku
, p. 457 - 474 (2007/10/02)
Various α,β-unsaturated ketones (9, 12 and 16) were prepared from 2-alkanol-1-methyl-1H-imidazoles (6, 10 and 13, respectively), which were obtained by treatment of 2-acyl-1-methyl-1H-imidazoles (1) with vinylic Grignard reagents, a lithium acetylide and allylic Grignard reagents, respectively. dl-(ar)-Turmerone (16i) was also synthesized as an application of the present methodology.
Synthese de cetones a partir de N-phenyl imidothioesters et par l'intermediaire de cetenimines
El-Jazouli, Mustapha,Lage, Nadia,Masson, Serge,Thuillier, Andre
, p. 883 - 888 (2007/10/02)
The thermal decomposition of metallated N-phenyl imidothioesters (lithium or magnesium alkylthio-enaminates generated by either deprotonation or 1,4-addition) led to ketenimines which were trapped in situ by organo-lithium or magnesium compounds to give metallated imines, readily hydrolysed into ketones.This sequence allowed the use of imidothioesters as acyl cation equivalents and also successive and regioselective > 1,3-additions of two different organometallics to an α-unsaturated imidothioester.Ar-turmerone, 2,6-dimethyl-2,7-octadien-4-one, iso-artemisia ketone, α-atlantone and other unsymmetrical ketones were synthesized by this procedure.
172. β-Cleavage of Bis(homoallylic) Potassium Alkoxides. Two-Step Preparation of Propenyl Ketones from Carboxylic Esters. Synthesis of ar-Turmerone, α-Damascone, β-Damascone, and β-Damascenone
Snowden, Roger L.,Linder, Simon M.,Muller, Bernard L.,Schulte, Karl H.
, p. 1858 - 1878 (2007/10/02)
The transformation of 36 bis(homoallylic) alcohols VII to alkenones IX and X via β-cleavage of their potassium alkoxides VIIa in HMPA has been investigated (cf.Scheme 2).These studies have established an order of β-cleavage for 2-propenyl, 1-methyl-2-propenyl, 2-methyl-2-propenyl, 1,1-dimethyl-2-propenyl, and benzyl groups in alkoxides 49a-56a and have allowed a comparison between the β-cleavage reaction and the oxy-Cope rearrangement in alkoxides 74a-83a.As illustrative synthetic applications, a two-step preparation of propenyl ketones 15-42 from carboxylic esters is described, together with syntheses of ar-turmerone (48), α-damascone ((E)-71), β-damascone ((E)-109), and β-damascenone ((E)-111).
A New Route to Unsymmetrical Ketones from Thioimidates via Ketenimines; a One-pot Synthesis of ar-Turmerone
Jazouli, Mustapha El,Masson, Serge,Thuillier, Andre
, p. 1598 - 1599 (2007/10/02)
Ketones may be synthesised by the generation and thermal decomposition of thio-N-metallated-enamines followed by trapping of the resulting ketenimines with an organometallic reagent.
