2-Methyl-4-butanolide

Dagegen wird 3-Carboxy-furan mit Lithium zur 2 -Melhyl-bernsteinaldehydsdure reduziert, die als 4-Hydroxy-2-methyl-4-butanolid vorliegt1 (Reduktion einer C=C-DoppeI-bindung) ... 

G.2) 2(3/f)-Furanone, dihydro-3-methyl-, 2-methylbutano-4-lactone, tetrahydro-3-methyIfuran-2-one, 2-methyl-4-butanolide, 4-hydroxy-2-methylbutanoic acid lactone, a-methyl-7-butyrolactone 1679-47-6] ( )- [69010-09-9] (/ )- [55254-35-8] (5)- ]65527-79-9]... 

Methyl-4-butanolide (55b) was identified in cocoa (358), coffee (594), passion fruit (711), mushrooms (644) and wine (547), while 2-isopropyl-4-butanolide (55c) was found in Burley tobacco (111). 

Aj, A2, B, B2, Cj, C2 (3-8), are three pairs of 2-alkylidene-3-hydroxy-4-methyl butanolides. The alkyl side chains are terminated with an ethyl (C-series), ethynyl (A-series), or ethynyl group (B-series). The two components in each pair are geometrical cis- and tra 5-isomers at the double bond conjugated with the lactone ring. It should be remembered that the carbon numbers of litsenolide Ci and C2 are two units larger than those of litsenolide Aj, A2, Bj and B2. 

Morino, A., Kuwahara, Y., Matsuyama, S. and Suzuki, T. (1997). ( ,)-2-(4/-Methyl-3 -pentenylidene)-4-butanolide, named /i-acariolidc a new monoterpene lactone from the mold mite, Tyrophagus putrescentiae (Acarina Acaridae). Bioscience, Biotechnology and Biochemistry 61 1906-1908. 

When butanolides are methylated it is again the carbonyl oxygen atom that is attacked. In this case the substrate is behaving like any other ester and no special furan feature seems to be involved. The products are exemplified by the simplest furylium cation (101) which is considered to adopt the conformation shown (80CJC164). 

Diketene is quantitatively hydrogenated to 3-methyl-3-propanolide in 92% ee (eq 9). Certain 4-methylene- and 2-alkylidene-4-butanolides as well as 2-alkylidenecyclopentanone are also hydrogenated with high enantioselectivity. ... 

Dimethyl 3-(2-methyl-l-propenyl)-2,2-dimethylcyclopropane-l,l-dicarboxylate (324) is synthesized by the reaction of (2-halo-2-methylpropylidene)malonate (291) with 2-methyl-l-propenylmagnesium bromide (323). The cyclopropane is accompanied by the malonoester (325) and a butanolide (326) formed by nucleophilic attack of an ester enolate (equation 101) . ... 

Analog wird u. a. 5-Oxo-5-phenyl- (74%) bzw. 5-(5-Methyl-2-thienyl)-5-oxo-4-butanolid (81%) erhalten. 

Zur Cyclisierung von 3,4-Dihydroxy-3-methyl-butansaure-ethylester zum 3-Hydroxy-3-methyl-4-butanolid (60%) s.Lit.208 ... 

The spiro-dihydrofuran (61) is converted into the cyclobutane derivative (62) under the influence of trifluoroacetic acid. The lithium dienolate (64), derived from the furanone (63), yields solely y-alkylated products on treatment with alkyl halides. Thermolysis of the t-butylperoxybutenolide (65) produces about equal amounts of the hydroxy-furanone (67) and the indenone (68), presumably via the oxide radical (66). Attack of iodide ion on the salt (69) results in the formation of methyl iodide, butanolide, and (surprisingly) methyl 4-iodobutanoate. A description of a study of the photochemical rearrangement of the tetrahydrofurans (70) to the bicyclic oxetans (71) has been presented. ... 

Palecek, J. Kvicala, J. Paleta, O. Fluorinated butanolides and butenolides Part 9. Synthesis of 2-(trifluoromethyl)butan-4-olides by Wittig reaction using methyl 3,3,3-trifluoropyruvate. J. Fluorine Chem. 2002, 113, 177-183. 

N.m.r. Studies involving Fluorinated Chemical Shift Reagents.— The determination of the cis-trans composition of methyl elaidate-oleate [Eu(fod)3] assignment of diastereotopic protons in amphetamine [Euffodls] " induced shifts of anils [Euffod)]] conSguration of 4-substituted-2-hydroxy-4-butanolides [Eu(fod)3] structure ofthietan 1,1-dioxide derivatives [Eu(fod)3l ... 

Initially, pilocarpine structure was incorrectly attributed as a betaine derivative of a pyridine-lactic acid compound. Further research, based rai chemical degradation, synthesis, and X-ray analysis, provided pilocarpine structure as (25,3/ )-2-ethyl-3-[(l-methyIimidazol-5-yl)methyl]-4-butanolide, as extensively described in previous reviews [8],... 

Lavender oil has been reported to contain more than 100 components, including linalool, linalyl acetate, lavandulyl acetate, terpinen-l-ol-4, 1,8-cineole, camphor, 3-phellandrene, terpinolene, a-thujene, n-hexanal, n-heptanal, methyl amyl ketone, ethyl amyl ketone, perillaldehyde, perillyl alcohol, r/-bomeol, a-terpineol, a-pinene, limonene, lactones (4-butanolide, dihydrocoumarin, 4-methyl-4-vinyl-4-butanolide, 5-pentyl-5-pentanolide, 4,4-dimethyl-2-buten-4-olide, etc.), sesquiterpenes (caryophyllene, cadinene, etc.), fatty acids (propionic acid, isobutyric acid, caproic acid, p-coumaric acid, etc.), and others (list and horhammer). " ... 

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