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• 6372-63-0 9,10-dihydro-9,10-ethano-anthracen-11-one 
• 1826-67-1 vinyl magnesium bromide 
• 6372-63-0 9,10-dihydro-9,10-ethanoanthracen-11-one 
• 3536-96-7 vinylmagnesium chloride 

Relevant academic research and scientific papers

Synthesis of Three Helically Chiral Iptycenes

The synthesis of iptycenes 2-4, each of which is helically chiral and has C2 symmetry axis, is described.Key intermediates are diene 7, prepared in two step and 44percent yield from known ketone 5, and anthracene 11, prepared in four steps and 48percent yield from diene 7.A noteworthy step in the latter sequence is the aluminum chloride catalyzed, room-temperature, regio- and stereoselective cycloaddition of naphthoquinone 8 to diene 7 to give a single isomer of 9.Anthracene 11 was converted in one step to 2 and in four steps to 3 (Scheme II).Bicycloalkene 15, an intermediate in the latter synthesis, was converted to 4 in two steps (Scheme III).Cycloaddition of unactivated dienophile 15 to unactivated dienes 17 and 18 proceeds in good yields.Hydrocarbon 3 could be resolved on several chiral columns.

Reactions retrodieniques - XVIII. Synthese par thermolyse eclair et etude d'allenes fonctionnels reactifs

The flash thermolysis of anthracenic Diels-Alder adducts leads to the obtention and low temperature spectroscopic characterization (ir, 1H and 13C nmr) of allenes 1-11 (see table 1).Butadienal 1, the simplest α-allenic aldehyde, is thus obtained from its precursors 13, 14 or 17.Thermolysis of the intermediate allylic alcohol 15 gives buta-1,3-dien-2-ol 18, which tautomerizes to methylvinylketone even at -100 deg C.An attempted synthesis of a natural δ-allenic ester, methyl laballenate 19, was undertaken using this method; however, the thermolysis of ester 24 leads via 19 to methyl acrylate and (Z + E) pentadeca-1,3-diene 25, resulting formally from a retroene cleavage of 19.Thermolyses of related esters 26 and 27 give in the same way the corresponding 1,3-dienes.Allenes with gem electron attracting groups are very reactive compounds acting as ketene equivalents in nucleophilic additions and or dipolar cycloadditions.The thermolysis of adducts 28-32, obtained by Knoevenagel condensation of malonic derivatives with ketone 16, leads to the following allenes of this series: 1,1-dicyano-1-methoxycarbonyl propadiene 4, 1,1-bis-(ethoxycarbonyl) propadiene 5 and 1,1-bis-(methoxycarbonyl) propadiene 6.Yields and purity are lower in the case of 3 and 5, owing to the presence of the thermolabile ethoxycarbonyl groups.The possibility of performing nucleophilic additions to the most polymerizable of these allenes: 1,1-dicyanopropadiene 2, is demonstrated by its clean, good yield additions at -50 deg C with methanol, methyl lithium, aniline ir dimethylamine.Allenes O or N-substituted on the allenic carbon are often reactive substances and are known mainly in the case of alkyl ethers and tertiary amines.The flash thermolysis of allylic alcohol 38 gives in good yield propanediol 7 which tautomerizes into acrolein at -50 deg C.Trimethylsilyloxypropadiene 8, 1-trimethylsilyloxybuta-1,2-diene 9 and 3-trimethylsilyloxybuta-1,2-diene 10 could also be obtained from their precursors 40, 44-46.Thermolysis of amine 49 leads in the same way to propadienamine 11, a reactive enamine postulated as a cosmic species and tautomerizing at -65 deg C into 1-azabuta-1,3-diene 50.