Convenient preparation of 3-alkylcyclopentenones from alkylcyclopentadienes

Collins, Scott; Hong, Yaping; Kataoka, Mitsuru; Nguyễn, Thu Hà

doi:10.1021/jo00297a080

Cited by 18 publications

(4 citation statements)

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“…A solution of 6,6-pentamethylenefulvene (10.0 g, 68.4 mmol) in diethyl ether (25 ml) was added to lithium aluminum hydride (2.70 g, 73.0 mol) in diethyl ether (200 ml) and the mixture was stirred for 0.5 h. The reaction mixture was quenched with water, then 10% HCI, extracted with diethyl ether, dried (MgSO 4 ), and concentrated (10.30 g, 94% yield) The product was sufficiently pure to be used without further purification and was spectroscopically identical to that previously reported [15].…”

Section: Syntheses 1-cyclohexylcyclopenta-13-diene (Iia)supporting

confidence: 59%

Synthesis and properties of sterically congested cyclopentadienes and their transition metal complexes

Clark

Killian

Luthra

et al. 1993

Journal of Organometallic Chemistry

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Abstract:The synthesis of 1,3-dialkyl substituted cyclopentadienes, C 5 H 4 RR', Cp'H (Va-g) (where R and R' are tert-butyl, isopropyl, neo-pentyl, cyclohexyl, or 1-methylcyclohexyl) is reported. These are synthesized by the nucleophilic addition of methyl or hydride anions to the corresponding 2-alkyl-6,6-dialkylfulvenes (IIIa-f) followed by hydrolysis. These substituted 1,3-cyclopentadienes have been converted to organometallic derivatives such as [Cp'Fe(CO) 2 ] 2 , [Cp'M(CO) 3 Me] (M = Mo or W) and Cp' 2 Fe. The spectroscopic and electrochemical properties of selected complexes have been investigated to probe the steric and electronic properties of the substituted cyclopentadienyl ligands.Article:

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Section: Syntheses 1-cyclohexylcyclopenta-13-diene (Iia)supporting

confidence: 59%

Synthesis and properties of sterically congested cyclopentadienes and their transition metal complexes

Clark

Killian

Luthra

et al. 1993

Journal of Organometallic Chemistry

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“…A literature survey revealed that compounds similar to 6 undergo rearrangement of the double bond in the presence of acid or strong base. − Therefore, we expected 6 would also rearrange to 2-cyclopentenone in the presence of the base DBU. A study by NMR involving treatment of 6 in CD 3 CN with a catalytic amount of DBU showed the conversion of 6 to 2-cyclopentenone.…”

Section: Resultsmentioning

confidence: 95%

Process Development of (1S,2S,5R,6S)- Spiro[bicyclo[3.1.0]hexane-2‘,5‘-dioxo-2,4‘-imidazolidine]-6-carboxylic Acid, (R)-α-Methylbenzenemethanamine Salt (LSN344309)

Rasmy

Vaid

Semo

et al. 2005

Org. Process Res. Dev.

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Process development and a pilot-plant process for the synthesis of 4 and its resolution to obtain (1S,2S,5R,6S)-spiro[bicyclo-[3.1.0]hexane-2′,5′-dioxo-2,4′-imidazolidine]-6-carboxylic acid, (R)-r-methylbenzenemethanamine salt (5) are described. Starting from the inexpensive raw 2-cyclopenten-1-one and sulfur ylide 1 the racemic bicyclo keto ester 2 was synthesized. Reaction of 2 with potassium cyanide and ammonium carbonate under Bu 1cherer-Berg's reaction conditions affords racemic 3 in 80% yield. Hydrolysis of 3 followed by the resolution with (R)-(+)-r-methylbenzylamine gave 4 in excellent yield and purity under optimized conditions. The improvement of the original discovery process to accommodate safety and environmental requirements for scale-up in manufacturing facilities is also discussed.

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“…as steps in the synthesis of natural products (cf. 2.3.3) and including pyranones [144], sialyl alcohols [145], glucals [146], pyrrolidinones [147], bicyclic ketones [148], acetals [149], synthesis of a vinyl oxirane [49], 3-alkylcyclopentenones [150] and hydroxycyclopentene [151]. Examples of lactolto-lactone oxidations effected by TPAP/NMO/PMS/CH 2 Cl 2 include a step for thapsigargin syntheses [152,153], and TPAP/NMO/PMS/CH 3 CN [64] for a tetrol to lactone oxidation [152].…”

Section: Specific Examplesmentioning

confidence: 99%

Oxidation of Alcohols, Carbohydrates and Diols

Griffith

2009

Catalysis by Metal Complexes

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This is one of the most important classes of oxidation effected by Ru complexes, particularly by RuO 4 , [RuO 4 ] − , [RuO 4 ] 2− and RuCl 2 (PPh 3 ) 3 , though in fact most Ru oxidants effect these transformations. The chapter covers oxidation of primary alcohols to aldehydes (section 2.1), and to carboxylic acids (2.2), and of secondary alcohols to ketones (2.3). Oxidation of primary and secondary alcohol functionalities in carbohydrates (sugars) is dealt with in section 2.4, then oxidation of diols and polyols to lactones and acids (2.5). Finally there is a short section on miscellaneous alcohol oxidations in section 2.6.In this chapter the first of the two most important categories of oxidations catalysed by Ru complexes (the other being alkene and alkyne oxidations in Chapter 3) are considered. The approach in this and subsequent chapters differs from that of Chapter 1, concentrating here on the substrate rather than on the oxidant. The text is divided into the categories of alcohols and their oxidations. There are summaries in section 2.3.6 of systems of limited applicability which are mentioned only in Chapter 1, and in section 2.3.7 of large-scale (>1 g) oxidations.The first oxidations of alcohols by stoicheiometric RuO 4 /H 2 O were reported in 1958, of primary alcohols to aldehydes or carboxylic acids and secondary alcohols to ketones [1]. The first Ru-catalysed oxidation of an alcohol was reported in 1965 when Parikh and Jones used RuO 2 /aq. Na(IO 4 )/CCl 4 1 ( Table 2.3) [2] to oxidise secondary alcohol groups in carbohydrates.Oxidation of alcohols is the most frequently reviewed topic for Ru-catalysed oxidations [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Mechanisms of alcohol oxidation by Ru complexes have been reviewed [21].

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Convenient preparation of 3-alkylcyclopentenones from alkylcyclopentadienes

Cited by 18 publications

References 1 publication

Synthesis and properties of sterically congested cyclopentadienes and their transition metal complexes

Synthesis and properties of sterically congested cyclopentadienes and their transition metal complexes

Process Development of (1S,2S,5R,6S)- Spiro[bicyclo[3.1.0]hexane-2‘,5‘-dioxo-2,4‘-imidazolidine]-6-carboxylic Acid, (R)-α-Methylbenzenemethanamine Salt (LSN344309)

Oxidation of Alcohols, Carbohydrates and Diols

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