Direct carbon alkylation of cyclic α-diketones

Kende, Andrew S.; Eilerman, Robert G.

doi:10.1016/s0040-4039(00)72437-3

Cited by 20 publications

(2 citation statements)

References 5 publications

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“…solubilize the salt of 8. The mixture was heated at 55 °C for 4 h after which time the solution was basified (NaHCOs solid) and extracted with CHC13. The volatiles were removed and the residue acidified to ~pH 2 with 0.1 N HC1.…”

mentioning

confidence: 99%

Synthetic elaboration of diosphenols. Part 3. Replacement of enolic oxygen by hydrogen

Ponaras¹,

Zaim²,

Pazo³

et al. 1988

J. Org. Chem.

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mentioning

confidence: 99%

Synthetic elaboration of diosphenols. Part 3. Replacement of enolic oxygen by hydrogen

Ponaras¹,

Zaim²,

Pazo³

et al. 1988

J. Org. Chem.

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“…Thus, 3-methyl-2-hydroxycyclopent-2-en-1-one (cyclotene) and 3-ethyl-2-hydroxycyclopent-2-en-1-one have been obtained in 60 and 56% yield, respectively, by the treatment of 2-hydroxycyclopent-2-en-1-one (2c) with two equivalents of n-butyllithium, followed by the addition of four equivalents of the corresponding alkyl iodide (Scheme 2). 27 Our strategy allows a novel access to various 3-alkyl-2-hydroxycyclopent-2-en-1-ones, in two steps from cyclopentene oxide (1c). Cyclotene-like com- pounds may also be easily converted into their ketoenamine derivatives, which have recently been involved in the study of the 'cooling' effect.…”

Section: -Hydroxycyclopent-2-en-1-one (2c) and Access To Cyclotene-lmentioning

confidence: 99%

Catalytic epoxide oxidation: a novel access to ﬂavouring and odorant α‐diketones

Antoniotti

Alezra²,

Fernández

et al. 2004

Flavour & Fragrance J

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The catalytic oxidation of epoxides to α α α α α-diketones provides a novel access to a variety of flavouring compounds and odorants. This alternative synthetic strategy involves an oxidation reaction catalysed by commercially available reagents and affords four cyclic and acyclic α α α α α-diketones presenting interesting organoleptic properties. ). α-Diketones also constitute useful intermediates for the synthesis of alkylpyrazines, a class of nitrogen-containing heterocycles used for their roasted nut notes, formed by the condensation of α-diketones with diamino compounds and subsequent dehydrogenation reaction.9 Applications of α-diketones as deodorants have been also reported. 10Some α-diketone syntheses applied to flavouring compounds involve the acid-catalysed rearrangement of the corresponding α,β-epoxyketones, 11 oxidation 12 or electrooxidation 13 of alkynes, or halogenation of carbonyl compounds followed by acidic hydrolysis.14 In this paper, we present our results concerning the alternative synthesis of useful flavouring α-diketones from the one-pot oxidation of the corresponding epoxides, in a catalytic system based on the use of bismuth and molecular oxygen in DMSO. Experimental GCGC analysis were carried out using a Hewlett-Packard 6890N gas chromatograph with two FID detectors, under the following conditions: vector gas, He; injector and detector temperatures, 250°C; split ratio, 1:50; constant flow, 1 ml/min; HP1 column, polydimethylsiloxane (50 m × 0.20 mm i.d., film thickness 0.33 µm) and INNOWAX column, polyethyleneglycol (50 m × 0.20 mm i.d., film thickness 0.2 µm); temperature programme, 60-250°C at 2°C/min and 250°C for 10 min. Retention indices were determined using C 5 -C 28 alkane standards as reference.

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