Butanolide, 2-hydroxy-4-

Bernsteinsaure-imide werden zu 4-Hydroxy-butansaure-amiden reduziert2 3, wobei auch hier 4-Butanolide anfallen2. 

S )-3-Hydroxy-4-butanolide (1), which is readily available from (—)-(S)-malic acid, can be converted into the dianion and the latter alkylated with alkyl halides or mesylates with moderate yields but with high diastereoselectivity (d.r. >98 2)39. 

Auf ahnliche Weise wird aus 3-Amino-2-oxo-tetrahydrofuran (2-Amino-4-butanolid) 4-(2-Hydroxy-ethyl)-2-mercapto-imidazol hergestellt149. 

Viridifloric /3-lactone, 143, has been identified as one of the pheromone components of a complex mixture of volatiles released by the pheromone glands of the male Idea leuconoe butterfly during courtship <1996BMC341>. A racemic mixture of both diastereoisomers was synthesized in four steps from the dilithio salt of 3-methylbutyric acid 144 alkylation with ethanal, dehydration of the secondary alcohol with phosphorus pentoxide, dihydroxylation of the C-C double bond with osmium tetraoxide, and finally formation of the /3-lactone by cyclization with sulfonyl chloride. By comparison with the sample isolated from I. leuconoe, the absolute configuration was established to be (2V,3V)-2-hydroxy-2-(l-methylethyl)-3-butanolide 143. 

In 1973 Dopke and Miicke studied the reaction between the oxolactone 62 with 5-chloro-l-methylimidazol-2-yl lithium and prepared 3-(5-chloro-1 -methylimidazol-2-yl)-2,2-diethyl-3-hydroxy-4-butanolide (63). They found that the carbonyl activity of the lactone ring thus substituted had been... 

An organoleptic omission test on this mixture confirmed 3-hydroxy-4, 5-dimethyl-2(5H)-furanone to be the most important FIC for a raw cane sugar aroma, and the other main components in Table 1, i.e., vanillin, maltol, 4-pentyl butanolide, 4-vinyl phenol and 2,6-dimethoxy phenol, seemed to improve the overall sugary aroma. From these results, we( ) gave the trivial name sotolon" to 2-hydroxy-4,5-dimethyl-2(5H)-furanone, which is built up from "soto" (raw sugar in Japanese) and "olon" (enol lactone) as a main FIC in raw cane sugar. 

The ee values in the enantioselective deprotonation are independent of the size of the attached alkyl residue. The method tolerates several substituents, e.g. 2- or 3-dibenzylamino, 3- or 4-(A(A-dialkylcarbamoyloxy), or 4-TBDMSO. Essentially enantiopure 2-hydroxy acids, 3-amino alkanols, 7-amino alkanols, cyclopropyl carbamates, and 2-hydroxy-4-butanolides " were obtained. Extraordinary high (>70) kinetic H/D isotope effects were observed in the deprotonation of chiral 1-deuteroalkyl carbamates. Kinetic resolution of racemic alkyl carbamates was achieved. ... 

The condensation of the dilithio derivative of (R)-(+)-3-(p-tolylsulfinyl)propionic acid with protected glycoaldehy-des (O-r-butyl and 0-benzyl) gives 5-alkoxy-4-hydroxy-3-(p-tolylsulfinyl)pentanoic acids, which spontaneously cyclize to the corresponding 3-sulfinyl-4-alkoxymethyl butanolides (eq 4). Pure diastereomers can be separated by flash chromatography and are obtained in comparable amounts. The corresponding optically pure butenolides are obtained by pyrolytic elimination of the sulfoxides and then transformed into natural (-i-)-(/ )-umbelactone (eq5). 

Figure 2. Examples of Various Lactone Moieties in Annonaceous Acetogenins an a, p-Unsaturated-y-lactone [Annonin I (4)], a C(4)-Hydroxylated a, P-Unsaturated-y-lactone [Bullatacin (5)], a Rearranged Acetonyl Butanolide [Bullatacinone (6)], and a Saturated p-Hydroxy-y-lactone [Itrabin (7)].

Figure 20. Base-catalyzed Conversion of 4-Hydroxy Butenolide Acetogenins (A2) Into Rearranged Butanolides (A3).

Die Reduktion mit Bis-[l,2-dimethyl-propyl]-boran verliiuft aufgrund der abgestuften Reaktivitat langsamer als mit Boran und 1,1,2-Trimethyl-propyl-boran ab, dafiir kann aber selektiv die Aldehyd-Stufe abgefangen werden114,115. 4-Butanolid wird so in guter Ausbeute zum 4-Hydroxy-butanal reduziert ... 

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]... 

Die Bildung der Hydroxy-ester IV bzw. 2-Cyan-4-butanolide V sowie der 4-Butanolide VI ist von geringer Bedeutung. 

Hydroxy-2-methylen-4-butanolide (haufig Bausteine von Naturstoffen) werden leicht aus den 1-Acyl-glycosiden I197-198... 

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

S)-3-Hydroxy-4-butanolide (149) is a useful precursor for the synthesis of natural products. It can be conveniently prepared by lactonization of diol ester 45a using trifluoroacetic acid (90% yield) [42] or sodium borohydride (83% yield) [2]. 

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. ... 

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 ... 

Deoxypentonic acid y-lactone, 9CI. 2-Hydroxy-4-hydroxymethyl-4-butanolide [74243-47-3]... 

Hydroxy-4-hydroxymethyl-4-butanolide. 3,4,5-Trihydroxypentanoic acid 1,4-lactone. 2-Deoxypentono-l, 4-lactone... 

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. 

Trunk wood of Mezilaurus synandra one of the species of Mezilaurus belonging to the same subtribe as Clinostemon, was shown to contain a similar y-lactone, (2/ ,3, 4S)-2-dodec-cu-enyl-3-hydroxy-4-methylbutanolide (41) (mp 72-76°C, [a]o -7.5 ) (115). The butenolide (42) from the same source is considered to be an artificial dehydration product of the 3-hydroxy-lactone (41). All of the above aliphatic y-lactones were isolated from Lauraceae 2-hy-droxy-4-(heptadec-8 -enyl)butanolide (43) obtained as an oil from the bark of Garcinia mannii (Guttiferae) is the only compound of this type found in other families (53). 

Pantothenic acid is a yellowish viscous oily liquid, which is readily soluble in water, alcohols, and dioxane, slightly soluble in diethyl ether and acetone, and virtually insoluble in benzene and chloroform. The stability of pantothenic acid in aqueous solutions is very pH dependent. It is most stable in slightly acidic medium (pH 4 to 5). Both in acidic and alkaline media it is hydrolytically cleaved to yield pantoic acid and its salts, respectively, and P-alanine. In acidic solutions, pantoic acid spontaneously eliminates one molecule of water, forming R)-2-hydroxy-3,3-dimethyl-4-butanolide (a-hydroxy-P,P-dimethyl-y-butyrolactone), referred to as pantoyl lactone or pantolactone (Fig. 4). 

The two epimeric 3-hydroxy-4-hydroxymethyl-4-butanolides 98 and 99 have been prepared from levoglucosenone (Schone 20). ... 

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