Lactones compounds

Terpenoid lactone compounds and their production process Ichikawa, K. Ikunaka, M. Kojima, N. Nishida, H. Yoshikawa, N.. European Patent. 0 933 373 Al, 1999... 

Immediate sodium borohydride (NaBfLt) reduction gave lactam 44. Bischler-Napieralski cyclization of 44 followed by NaBfLt reduction yielded ( )-methyl-0-acetyl-isoreserpate (45). The correct stereochemistry at C-3 was obtained by first lactonizing compound 45 epimerization with pivalic acid then resulted in ( )-reserpic acid lactone (47). Treatment with base followed by acylation with TMBCI yielded racemic reserpine. The stereochemical considerations involved in the epimerization reaction will be discussed later. 

Enolic structures were established in lactonic compounds 325a-c (64BCJ1460 71T6023) they are monobasic acids (325c pKa 3.57). In an early paper (58MI1) the lactim form of pyrazolotropone 388 was taken into account. In the case of diazepinotropone 95 (79MI3), the lactim form was preferred (81JHC335). 

Since the use of stoichiometric amounts of organostannane is unfavorable for the environment, they have established reaction conditions for a process that is catalytic in organostannane. Thus, the reaction with an alkenyl trichloroacetate as the precursor of the tin enolate in the presence of the catalytic amount of Me3SnOMe and the appropriate aldehydes afforded the corresponding aldol adducts with high enantio-and diastereoselectivities (Table 9.8).17 However, when the aliphatic aldehydes were used as substrates, the reaction did not take place at all. The proposed catalytic cycle is shown in Figure 9.3. It was also demonstrated that this catalytic system could be applied using a [3-lactone compound as an alkenyl trichloroacetate equivalent to... 

The development of a novel production system for D-pantoyl lactone (which is a lactone compound carrying a chiral hydroxy group and a chiral intermediate for the commercial production of D-pantothenate) by microbial asymmetric reduction has been undertaken. D-pantothenate is mainly used in various pharmaceutical products and as an animal feed additive, the current world production of calcium pantothenate being about 6,000 tons per year. Conventional commercial production of D-pantoyl lactone has depended exclusively on chemical synthesis involving optical resolution of a chemically synthesized racemic pantoyl lactone, which is the most troublesome step of the pantothenate synthesis process. 

Kataoka, M., Honda, K., Sakamoto, K., Shimizu, S. 2007 (in press). Microbial enzymes involved in lactone compound metabolism and their biotechnological applications. Appl. Microbiol. Biotechnol., 75, 257-266. 

Fukuyama [5] obtained the thioester 35 from the reaction of the thiocarboxylic acid anion 34 with the / -lactone compound 17. After acidic deprotection of the Boc group, the thiazoline ring is successfully closed in benzene under Dean-Stark conditions (35 —> 33) in yields between 60 and 80 %. Ehrler [6] and Pattenden [7] choose a more classical way. They close the thiazoline ring by condensation of the aminothiol hydrochloride 5 x HCl with a nitrile. The yields are generally modest (45 and 55 %) except in one case [6]. Installation of the necessary nitrile function hinders its repetitive use, as this procedure causes a considerable loss of material. Heathcock [8] and Ehrler [6 choose the thiol-amide 37 as a key compound. Titanium tetra-... 

D-Glucuronic acid215 and its 6,3-lactone216 combine readily with two equivalents of a thiol in the presence of hydrochloric acid (conditions of mercaptolysis) to give the dithioacetal (66) of the aldehydo form of the lactone. Compound 66 opens in sodium hydroxide216 or ammo-... 

The chiral mono-Cp cr-cyclohexadienyl compound shown in Scheme 201 has been synthesized. The reaction with benzaldehydes proceeds with excellent diastereoselectivity. This reactivity has been used for the synthesis of nephrosteranic acid and chiral lactone compounds.23... 

Armstrong, D.W. and Brown, L.A., Aliphatic, aromatic and lactone compounds, in Bioprocess Production of Flavor, Fragrance and Color Ingredients, Gabelman, A., Ed., Wiley, New York, 1994. 

The synthesis of the C1-C7 fragment, which corresponds to the lactone, starts with the homoallylic alcohol 2 which was prepared from 1. The existing stereocenter and the conjugate addition method of Evans [21] allow the control of the C5 stereocenter. The homoallylic alcohol 2 was oxidatively cleaved and homologated to the trans enoate 3 by a Wittig olefination. Treatment of 3 with benzaldehyde and a catalytic amount of KHMDS provided acetal 4. The internal Michael addition of the hemiacetal intermediate proceeds with complete stereoselectivity [22]. After deprotection and oxidation, the corresponding aldehyde was treated with Amberlyst-15 and then with camphor sulfonic acid (CSA), to yield pyrane 5 as a mixture of (3- and a-anomers (1.8/1). This compound was converted to the thiophenyl acetal 6 (4 steps) as this compound can be hydrolyzed later under mild conditions (Hg +) with subsequent oxidation of the lactol to the desired lactone. Compound 6 represents the C1-C7 fragment of discodermolide (Scheme 1). 

Macrolide-producing organisms are classified as shown in Table 11. Actino-mycetes produce the largest number of macrolides (more than 800). Myxobacte-ria produce about 100 macrolides, and the other bacteria produce about only 40 macrolides. A rather large number of macrolides have been isolated from fungi (about 200). Lichens produce only three compounds. About 70 macrolides have been isolated from algae. Though plants produce about 700 macrocyclic lactone compounds, most of them are tannins or alkaloids such as pyrrolizidines. So they... 

Dekker, K. A., Aiello, R. J., Hirai, H., Inagaki, T., Sakakibara, T, Suzuki, Y, Thompson, J. F., Yamauchi, Y, and Kojima, N. (1998). Novel lactone compounds from Mortierella verticillata that induce the human low density lipoprotein receptor gene Fermentation, isolation, structural elucidation and biological activities. J. Antibiot. 51, 14-20,... 

In addition, 10-membered lactone compounds, namely, decarestrictines, were identified by chemical screening for inhibition of cholesterol biosynthesis using in vitro and in vivo assay systems. 3(3-Hydroxy-l,ll-dioxo-ergosta-8,24(28)-diene-4a-carboxylic acid was isolated as an inhibitor of cholesterol biosynthesis using human Chang liver cell system. 

Allergic skin reactions to chicory have been reported (Blumenthal et al. 1998), most likely due to the presence of sesquiterpene lactone compounds present in the fresh, unroasted plant material (Friis et al. 1975 Malarz et al. 2002 Pyrek 1985 Ross et al. 1993). 

Boneset contains sesquiterpene lactones, compounds that may cause allergic contact dermatitis in sensitive individuals (Herz et al. 1977 Warshaw and Zug 1996). 

An erythema-multiforme-like eruption following allergic contact dermatitis was reported after contact with elecampane, with the effects attributed to sesquiterpene lactone compounds (Mateo et al. 1995). 

Costus essential oil is used in perfumery and has been responsible for a number of cases of contact dermatitis (Cheminat et al. 1981). Sesquiterpene lactone compounds are believed to be responsible for the reaction (Cheminat et al. 1981 Pandey et al. 2007 Robinson et al. 2008 Sun et al. 2003). 

Chewing fresh leaves may induce a generalized inflammation of oral mucosa (Johnson et al. 1985), which is likely due to the sesquiterpene lactone compounds in the plant. These compounds were suggested as the cause for contact allergy to live feverfew plants (Hausen and Osmundsen 1983). 

Contact dermatitis from tansy has been reported and is attributed to sesquiterpene lactone compounds in the plant. Cross-reactivity has been reported between sesquiterpene lactone-containing plants in the Asteraceae family including tansy, dandelion, feverfew, and yarrow (Guin and Skidmore 1987 Hausen 1996 Hausen and Osmundsen 1983 Killoran et al. 2007 Mark et al. 1999 Opdyke 1979 Paulsen et al. 1993,2001). 

Contact dermatitis from fresh dandelion leaf has been reported and confirmed by patch testing. These reactions are generally attributed to the sesquiterpene lactone compounds in dandelion (Guin and Skidmore 1987 Hausen 1982 Ingber 2000 Jovanovic et al. 2003 Mark et al. 1999 Paulsen et al. 2008 Wakelin et al. 1997). 

Penicillic acid (5-hydroxy-5-isopropenyl-4-methoxy-2(5/f)furanone) [90-65-3] M 158.2, m 58-64 , 64-65 (monohydrate, acid), 83-84 , 87 (anhydrons, lactone), pK 5.9. The lactone (furanone, anhydrous) hydrolyses to the acid (3-methoxy-4-oxo-hexa-2,5-dienoic acid, hydrate). It crystallises from water as the monohydrate (acid), or from petroleum ether as the anhydrous (lactone) compound. The free acid is in equilibrium with the lactone. Its UV has t 221iun (s 12,500) in 0.02M KOH 228mn (s 11,500) in 0.02M HCl [Raphael J Chem Soc 1508 1948. [Beilstein 3II519,3 HI 1467.] It is a possible antineoplastic. 

All esters discussed so far are acyclic molecules (this means they do not contain rings), but there are also cyclic esters, where both the acyl carbon and the alcohol oxygen are constituent members of a ring, as in 88-90. These cyclic esters are called lactones. The common names for structurally simple lactones arise by using the suffix for the open chain carboxylic acid precursor and the word lactone. Compound 88 is y-butyrolactone and 89 is 6-valerolactone, where the name is taken from the common names for the four-carbon acid (butyric acid) and the five-carbon acid (valeric acid). The lUPAC names are based on the cyclic ether, so 88 is 2-oxoolane and 89 is 2-oxooxane. 

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