Ethyl benzylidene

An ethereal soln. of ethyl benzylidene-a-cyanoacetate added to excess ethereal diazomethane in an ice bath, and kept at least 16 hrs. at 0-5° —ethyl a-cyano- -phenylcrotonate. Y 99%.—This is an excellent route to the above products, particularly when the ketones needed to prepare them via a condensation (cf. Synth. Meth. 12, 808) are not easily available. F. e. s. F. D. Popp and A. Gatala, J. Org. Ghem. 26, 2738 (1961). 

Various 4-, 5-, or 4,5-disubstituted 2-aryIamino thiazoles (124), R, = QH4R with R = 0-, m-, or p-Me, HO C, Cl, Br, H N, NHAc, NR2, OH, OR, or OjN, were obtained by condensing the corresponding N-arylthiourea with chloroacetone (81, 86, 423), dichloroacetone (510, 618), phenacyichloride or its p-substituted methyl, f-butyl, n-dodecyl or undecyl (653), or 2-chlorocyclohexanone (653) (Method A) or with 2-butanone (423), acetophenone or its p-substituted derivatives (399, 439), ethyl acetate (400), ethyl acetyl propionate (621), a- or 3-unsaturated ketones (691), benzylidene acetone, furfurylidene acetone, and mesityl oxide in the presence of Btj or Ij as condensing agent (Method B) (Table 11-17). 

H-Pyran, 2-alkoxy-4-methyl-2,3-dihydro-conformation, 3, 630 4H-Pyran, 2-amino-IR spectra, 3, 593 synthesis, 3, 758 4H-Pyran, 4-benzylidene-synthesis, 3, 762 4H-Pyran, 2,3-dihydro-halogenation, 3, 723 hydroboration, 3, 723 oxepines from, 3, 725 oxidation, 3, 724 reactions, with acids, 3, 723 with carbenes, 3, 725 4H-Pyran, 5,6-dihydro-synthesis, 2, 91 4H-Pyran, 2,6-diphenyl-hydrogenation, 3, 777 4H-Pyran, 6-ethyl-3-vinyl-2,3-dihydro-reactions, with acids, 3, 723 4H-Pyran, 2-methoxy-synthesis, 3, 762 4H-Pyran, 2,4,4,6-tetramethyl-IR spectra, 3, 593 4H-Pyran, 2,4,6-triphenyl-IR spectra, 3, 593... 

C. The precipitated product is filtered, dried and recrystallized from ethyl acetate to give 5-fluoro-2-methyl-1-(p-methylsulfinylbenzylidene)-3-indenylacetic acid. Upon repeated recrystallization from ethylacetate there is obtained cis-5-fluoro-2-methyl-1-(p-methylsulfinyl-benzylidene)-3-indenylacetic acid (MP 184° to 186°C). 

Benzylacetophenone has been prepared by the reduction of benzalacetophenone with zinc and acetic acid1 and catalytic-ally with palladium and hydrogen 2 by the reduction of /3-duplo-benzylidene acetophenone monosulfide 3 by the oxidation of the corresponding car bind with chromic acid 4 by the hydrolysis of ethyl benzyl benzoylacetate 5 from acetophenone and benzyl chloride by the action of sodamide 6 and from benzoic and hydrocinnamic adds using as catalysts manganese oxide 7 and ferric oxide.8... 

Kurogoshi and Hori [ 104] determined the crystal structures of the mesogenic ethyl and butyl 4-[4-(4-n-octyloxybenzoyloxy)benzylidene]aminobenzoates. The compounds have different phase sequences crystal-smectic A-nematic-isotropic and crystal-smectic C-smectic A-nematic-isotropic for the ethyl and butyl compounds, respectively. Both compounds have layer structures in the solid phase. The butyl compound contains two crystallographically independent molecules. Within the layers, adjacent molecules are arranged alternately so as to cancel their longitudinal dipole moments with each other. In the ethyl compound the core moieties are almost perpendicular to the layer plane, while in the butyl compound these moieties are tilted in the layer. 

The Michael reaction of benzylidene acetophenone and benzylidene acetone with ethyl acetoacetate, nitromethane, and acetylacetone was studied by Musaliar and co-workers in the presence of a cetyltrimethy-lammonium bromide-containing aqueous micellar medium.50 The Michael reaction of various nitro alkanes with electrophilic alkenes is performed in NaOH (0.025-0.1 M) in the presence of cetyltrimethylam-monium chloride (CTACI) without any organic solvent (Eq. 10.23).51... 

L-alanylglycyl-L-cysteinyl-L-lysyl-L-asparaginyl-L-phenylalanyl-L-phenylalanyl-L-tryptophanyl-L-lysyl-L-threonyl-L-threonyl-L-cysteine 6-0-benzoyl-N-(benzyloxycarbonyl) methylamide 4,6-0-benzylidene-N-benzylidene-N-(benzyloxycarbonyl) methylamide N- (benzyloxy carbonyl) -N-(benzyloxycarbonyl)-, amide N-(benzyloxycarbonyl)-, hydrazide N-(benzyloxycarbonyl)-, methylamide N-(benzyloxycarbonyl)-, methyl ester N-(benzyloxycarbonyl)-L-alanyl-L-alanine methyl ester N-(benzyloxycarbonyl)-L-alanylglycine ethyl ester N-(benzyloxycarbonyl)glycyl-L-alanine methyl ester 3,4,6-tri-0-acetyl-2-amino-2-deoxy-N-(benzyloxycarbonyl)-, benzyl ester, hydrochloride... 

Ci9H2408Ss Ethyl 3,7-anhydro-6,8-0-benzylidene-4-deoxy-2-(ethyl-enedithio)-D-talo-2-octulosonate (ABTOET)265 P212121 Z = 4 Dx = 1.359 R = 0.045 for 1,520 intensities. The structure contains a fused pyranoid ring and a dioxolane ring. The conformation of the pyranoid part is a distorted 6C3, with Q = 57 pm, 6= 20°,

chair conformations of the dioxolane and the dithiene rings... 

C 9H24OgS2 Ethyl 3,7-anhydro-6,8-0-benzylidene-4-deoxy-2-(ethylene-dithio)-D-talo-2-octulosonate ABTOET 43 348... 

Apovincaminic acid ethylester was supplied by Richter Gedeon Co., (-)-dihydroapovincaminic acid ethyl ester was prepared according to the procedure described in (11). fSj-a, -diphcnyl-2-py rro 1 idincmethanol was synthesised as described (12). 2-benzylidene-l-benzosuberone was prepared as described in (13). Isophorone was supplied by Merck. Cinchonidine was purchased from Fluka. 

It is of interest that reaction of methyl, benzyl, and p-nitrophenyl 2-acetamido-4,6-0-benzylidene-2-deoxy-/3-D-glucopyranosides, and also the corresponding methyl a-D-glucopyranoside derivative, with ( )-2-chloropropionic acid gave, in preponderant yields, the respective 3-0-(D-l-carboxyethyl) derivatives257 only from the last-mentioned reaction was a significant amount of the 3-0-(L-l-carboxy-ethyl) derivative isolated. 

Benzophenone, conversion to ethyl /S-hydroxy-0,0-diphenylpro-pionate, 44, 57 Benzophenone oxime, 44, 52 Benzopyrazole, 42, 69 3-Benzoylpropionic add, condensation with benzaldehyde to give a-benzylidene-y-phenyl-A y -bu-tenolide, 43, 3 N-Benzylacetamide, 42,18 n-Benzyiacrylamide, 42,16 Benzyl alcohol, reaction with acrylonitrile, 42,16... 

Methyl 2-methyl-3-methylthio-4,6-benzylidene-/S-i>-idoside to methyl 2-methyl-3-de8Oxy-4,6-benzylidene-0-D-idoside Methyl 3-methylthio-5-L-xyloside to methyl 3-desoxy-/J-o-xyloside Ethyl thiol-D-ribonate tetraacetate to aldehydo-D-ribose tetraacetate Methyl thiol-D-gluconate pentaacetate to D-glucitol hexaacetate Ethyl tetraacetyl-0-D-glucopyranosyl xanthate to 1,5-anhydro-D-glucitol tetraacetate... 

The simple cleavage of lactones 1 or 2 with alcohol and acid has not been reported. However, when 1 is treated with benzaldehyde diethyl acetal and hydrochloric acid, ethyl 3,5 4,6-di-0-benzylidene-L-gulonate (47) is formed in >90% yield.77,78 No other isomers were observed, and other acetals of benzaldehyde, as well as aliphatic aldehydes, afford similar products in good yield.77 D Addieco prepared36 similarly protected derivatives of L-gulonic acid by oxidation of l,3 2,4-di-0-ethylidene-D-glucitol (15), followed by esterification of the resulting acid with diazomethane. 

Preparation of the donor 46 was started from 4,6-0-benzylidene protected thiomannoside 47 (Scheme 7.24). Alkylation with p-allyloxybenzyl chloride under phase transfer conditions78 was followed by 3-O-silylation and Pd(0)-mediated deallylation79 to give 48. The phenolic OH group was alkylated with ethyl 6-bromohexanoate and carboxylic acid, liberated by alkaline hydrolysis, was reacted with PEG monomethyl ether (MW -5000) under Mitsunobu conditions to afford 46. 

---