Di benzylidene acetone

Using benzaldeliyde and acetone, he obtained mono- and di-benzylidene acetone. 

Dilute sodium hydroxide was used as a condensing ent by J. G. Schmidt and the method was applied by Claisen and collaborators to the s3mthesis (Claisen reaction) of aromatic ketonic esters, e.g. benzylidene acetone and di-benzylidene acetone from benzaldehyde and acetone. An alternative method was the use of an aromatic aldehyde or ketone with acetoacetic ester in presence of hydrogen chloride. Benzoylacetic ester, CgHgCO CHe-COOCoHs, was obtained by condensing benzoic and acetic esters in presence of sodium ethoxide, and j8-diketones by condensing ketones and acid esters, e.g. acetyl-acetone CHaCO-CHaCOCHg."... 

Related Fe-C=C-NCNH (35) in which the NCNH and the Fc moieties are separated by an aeetylide unit is accessible from FcC CH by applying the Sonogashira cross-coupling protocol. Lithiation of 35 and reaction of 35-Li with stoichiometric amounts of [(Et2S)2MCl2] (M = Pd, Pt) produced Fc-C=C-NCN-MCl (36a, M = Pd 36b, M = Pt) [49, 50]. The introduction of a Pdl imit into ferrocene NCN pincer molecules is realizable by the oxidative addition of the earbon-iodide bond in Fc-NCN-1 or Fc-C=C-NCN-l to palladium (e. g., [Pd2(dba)3], dba = di(benzylidene) acetone). After appropriate work-up, complexes Fc-NCN-Pdl (33c) and Fc-C=C-NCN-Pdl (35c) could be isolated in good yields. 

An enormous variety of olefinic types have been found to undergo such solid-state (2 + 2) photocyclodimerizations. These include cinnamic acids (128,132) derivatives of cinnamic acids such as esters (133) and amides (134) styrene derivatives (135) stilbenes (136) aliphatic mono- (137), di- (138), and triene (139) dicarboxylic acids and derivatives 1,4-diarylbutadienes (140) and their vinylogs (141), benzylidene acetones (142) and benzylidene acetophenones (143) ... 

Improved selective acylation of 4,6 4, 6 -di-0-benzylidene-a,a-trehalose was achieved in acetone by the following method, in which a gentle liberation of -acyl-imidazole occurs on the conversion of benzotriazolyl-iV-oxytris(dimethylamino)phos-phonium hexafluorophosphate with the carboxylic acid in the presence of triethylamine and addition of imidazole 1199 ... 

Acetalation. As polyhydroxy compounds, carbohydrates react with aldehydes and ketones to form cyclic acetals (1,13). Examples are the reaction of D-glucose with acetone and a protic or Lewis acid catalyst to form l,2 5,6-di-0-isopropylidene-a-D-glucofuranose [582-52-5] and its reaction with benzaldehyde to form 4,6-O-benzylidene-D-glucopyranose [25152-90-3]. The 4,6-0-(l-carboxyethylidine) group (related to pyruvic acid) occurs naturally in some polysaccharides. 

The acetonation of 2,4-benzylidene-D-sorbitol has been studied by Vargha135 and by Laan and Dekker 88 when copper sulfate is employed as the catalyst a mono- and a di-isopropylidene derivative (m. p. 179° and 131°, respectively) are obtained. An interesting point about the latter compound is that, unless acetal rearrangement occurs during the acetonation stage, it must contain at least one isopropylidene group which is not united to adjacent positions in the hexitol molecule. 

Optimum conditions for the electro-oxidation of l,2 5,6-di-Q-isopropylidene-a-D-glucofuranose to the corresponding 3-uIose have been developed In a study of the hydration of methyl 4,6-0-benzylidene-2-bromo- and 2-chloro-2-deo) -a- and -D-xvlo-hexopvranosid-3-ulose in acetone solution, only the fl-D-xylo-derivatives were observed to hydrate and in another investigation the isomeric composition of freshly prepared D-ribo-hexos-3-ulose in DjO has been examined by H-n.m.r. spectroscopy. Full details have been published on the regioselective monooxidation of unprotected glycosides by reaction of Q-stannyl derivatives with bromine. ... 

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