Synthesis of (E)- and (Z)-pulvinones

Abstract

Two new routes to pulvinones have been developed, one of which involves a novel Wittig reaction. For the first time, members of the €-series, including the parent ( E ) -pulvinone, are reported and the structural elucidation of the geometric isomers is described. A method for quantitatively converting (E)pulvinones into (Z) -pulvinones is presented, together with a technique for differentiating between the isomers. P h H(2)p u l v i none ([)-pulvinone I -(9a)f -(9a)

Crystal structure of (5′S,8′S)-3-(2,5-dimethylphenyl)-8-methoxy-3-nitro-1-azaspiro[4.5]decane-2,4-dione

“…For the pesticide spirotetramat, the central unit of the title compound, see: Fischer & Weiss (2008); Maus (2008); Bruck et al (2009); Campbell et al (1985); Schobert & Schlenk (2008). For structures of spirotetramat derivatives, see: Fischer et al (2010) Symmetry codes: (i) Àx þ 1; Ày þ 2; Àz þ 1; (ii) x; Ày þ 3 2 ; z À 1 2 ; (iii) Àx; y À 1 2 ; Àz þ 1 2 ; (iv) Àx; Ày þ 2; Àz þ 1.…”

“…Spirotetramat is a new systemic insecticide which chemically belongs to the class of spirocyclic tetramic acid derivatives and be developed by Bayer CropScience AG (Fischer et al, 2008;Maus, 2008). A unique mode of action coupled with a high degree of activity on targeted pests and low toxicity to nontarget organisms make spirocyclic tetronic acid compounds as a new tool for integrated pest management (Bruck et al, 2009;Campbell et al,1985;Schobert et al, 2008) In order to study the influence of new substituents on the activity of the Spirotetramat derivative, the title compound, has been synthesized and its structure has been determined ( Fig. 1).…”

3-(2,5-Dimethylphenyl)-8-methoxy-2-oxo-1-azaspiro[4.5]dec-3-en-4-yl 3-(2-bromo-4-fluorophenyl)acrylate

“…For the pesticide spirotetramat (systematic name: cis-3-(2,5dimethylphenyl)-8-methoxy-2-oxo-1-azaspiro[4.5]dec-3-en-4yl ethyl carbonate), the central unit of the title compound, see: Fischer & Weiss (2008); Maus (2008). For structures of spirotetramat derivatives, see: Fischer et al (2010); Campbell et al (1985); Schobert & Schlenk (2008); Zhao et al (2012); Wang et al (2011). For the metabolic transformation of spirotetramat, see: Bruck et al (2009).…”

“…Spirotetramat is a new systemic insecticide which belongs chemically to the class of spirocyclic tetramic acid derivatives and was developed by Bayer CropScience AG (Fischer et al, 2008;Maus, 2008). A unique mode of action coupled with a high degree of activity on targeted pests and low toxicity to nontarget organisms make spirocyclic tetronic acid compounds a new tool for integrated pest management (Bruck et al, 2009;Campbell et al,1985;Schobert et al, 2008).…”

Naphthyl Tetronic Acids as Multi‐Target Inhibitors of Bacterial Peptidoglycan Biosynthesis

“…[29] Deprotonation of 2 at C5 with lithium isopropylcyclohexylamide (LICA) [30] followed by an aldol reaction with substituted aldehydes 2 mediated by anhydrous ZnCl 2 afforded diastereomeric alcohols, which were converted into their mesylate or chloride derivatives in situ followed by elimination to generate the exocyclic double bond of 3 in the thermodynamically more stable Z configuration. [31] The key step involved a Suzuki cross-coupling of 3 with aryl boronic acids catalyzed by either [Pd- 2 ] to afford the methoxyfuranones 4 a-k. Demethylation of methoxyfuranones 4 a-k with lithium bromide [32] in the final step afforded the desired naphthylfuran-2ones 5 a-k. Purification by silica gel column chromatography was followed by an acid wash of the collected fractions to restore the acidic functionality.…”