Darzens condensation of .alpha.-halolactones. Glycidic lactones as intermediates in acetogenin synthesis

White, James D.; Bremner, John B.; Dimsdale, M. J.; Garcea, Robert L.

doi:10.1021/ja00730a064

Cited by 10 publications

(4 citation statements)

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“…Oxopyrazolin-spiro-oxirans (5) substituted with aryl groups on the oxiran ring (Table 2) are readily accessible from basic peroxide oxidation of the corresponding 4-arylidenepyrazolinones (4) ( The stereochemistry of arylidenepyrazolinones has been a subject of considerable study. Arylidenepyrazolinones (4a), (4b), (k), and (4f), among others, have been assigned the Z-…”

Section: Oxidation Of the Known 4-isopropylidenepyrazolinone (2a)mentioning

confidence: 99%

Oxopyrazoline-spiro-oxirans. A new class of reactive heterocycles

Eǧe¹,

Adams²,

GESS³

et al. 1983

J. Chem. Soc., Perkin Trans. 1

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Section: Oxidation Of the Known 4-isopropylidenepyrazolinone (2a)mentioning

confidence: 99%

Oxopyrazoline-spiro-oxirans. A new class of reactive heterocycles

Eǧe¹,

Adams²,

GESS³

et al. 1983

J. Chem. Soc., Perkin Trans. 1

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“…[5][6][7][8][9][10] The spiroepoxy lactone moiety annulated to other saturated carbocyclic rings is found in numerous natural products. [11][12][13][14] Monocyclic spiroepoxy lactones were synthesised by several methods, such as by Darzens reaction, [15][16][17][18][19] by intramolecular nucleophilic substitution at 2hydroxy-2-(2-hydroxymethyl)lactones or derivatives with other leaving groups, [20][21][22] via 2,4-dipolar cycloaddition of a-oxolactones with diazomethane 23 and by epoxidation of 2-ylidenelactones with hydrogen peroxide or m-chloroperbenzoic acid (MCPBA). 19,24,25 The synthetic potential of these compounds in particular in ring transformation reaction has not yet been explored.…”

mentioning

confidence: 99%

Synthesis of Hydroxyalkyl Heterocyclesby Ring Transformation of Spiroepoxy Lactones with Binucleophiles

Otto¹,

Liebscher²

2003

Synthesis

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Spiroepoxy lactones 2 and 3 were obtained by epoxidation of a-alkylidenelactones 1 with dimethyldioxirane. Reaction of spiroepoxy lactones 2 with binucleophiles gave access to a number of hydroxyalkyl heterocycles with interesting substituent patterns. Depending on both the kind of substituent at the oxirane ring as well as the type of the binucleophile, the spiroepoxy lactones react either as C 3 or as C 2 bielectrophilic building blocks giving 4-, 6-and 7membered partially saturated N-and S-heterocycles 5, 6, 8, 9, 11 and 13.

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“…Some of the methodologies reported in the literature to generate the 1,5dioxaspiro [2.4]heptane unit include the photochemical ring expansion of epoxycyclobutanones [11], Darzens condensation of a-halolactones [12], treatment of tetrahydrofuran-3-ones with dimethylsulfonium methylide [13], or epoxidation of 3-methylenetetrahydrofurans [14]. However, standard epoxidation of a-methylene-g-lactones, although this appears to be the most direct route to the corresponding epoxylactones, proved to be difficult because the exocyclic CC bond in these lactones showed very poor reactivity towards peracids, and nucleophilic epoxidation procedures led to polymeric materials [15].…”

mentioning

confidence: 99%

“…MS: 324 (1, M ), 295(12), 207(10), 183(12), 182 (37), 164(22), 155(16), 152(13), 142 (26), 141(10), 140 (66), 138(10), 136 (25), 133 (27), 124 (41), 122 (14), 114 (31), 112 (31), 100 (15), 99 (15), 98 (100), 96 (12), 86 (15), 84 (27), 72 (27), 70 (38), 56 (14), 55 (13). HR-MS: 324.2796 (C 19 H 36 N 2 O 2 ; calc.…”

mentioning

confidence: 99%