Carboxylic acids 7-lactonization

C2 2H2 8O3 f 17/3-Hydroxy-3-oxo-17a-pregna-4,6-diene-21-carboxylic acid 7-lactone, 42B, 403... 

Acetoxy-D-homo-androst-5-en-17a-one, 64 3 -Acetoxy-5/3-hydroxy-17-keto-B-noran-drostan-6/3-carboxylic acid lactone, 435 3/3-Acetoxy-5-hydroxy-B-norcholestan-6-carboxylic acid 5,6-lactone, 431... 

Pyrolyze to alkene and carboxylic acid Lactone Cyclic ester... 

The alkylation of metalated imines, hydrazones, 4,5-dihydrooxazoles, 4,5-dihydroisoxazoles, 5,6-dihydro-4/7-1,2-oxazines and 2,5-dialkoxy-3,6-dihydropyrazines (i.e., azaenolates) is a commonly used method in asymmetric synthesis of enantiomerically enriched aldehydes, ketones, spiroacetals, amines, /J-oxo esters, carboxylic acids, lactones, 1,3-amino alcohols, /(-hydroxy ketones and amino acids. 

Treatment of 6-chloro-2-hydroxy-6-methyltricyclo[5.4.0.015]undecane-7-carboxylic acid lactone with potassium to7-butoxide gave 2-hydroxy-6-methylenetricyclo[5.4.0.01,5]undecane-7-carboxylic acid lactone (15).178... 

Hydroxy-6-methylenetricyclo 5.4.0.0,5]undecane-7-carboxylic Acid Lactone (15) 178... 

A mixture of 6-chloro-2-hydroxy-6-mcthyltricydo[5.4.0.01,5]undecane-7-carboxylic acid lactone (300 mg, 1.25 mmol) and r-BuOK (561 mg, 5.00 mmol) in anhyd THF (5 mL) was stirred at rt for 20 min and 5% aq HC1 (10 mL) was added. The aqueous layer was extracted with Et20 (3x15 mL). The combined organic phases were washed with sat. Nall CO, and brine, and dried (MgS04). Evaporation and purification by flash chromatography (silica gel, 20% EtOAc/ hcxanc) afforded the alkene yield 180 mg (71%). 

Treatment of dehydro-L-ascorbic acid (72) with phenyl hydrazine followed by hydroxylamine yielded the hydrazone oxime (73a), cyclization of which in refluxing acetic anhydride gave 4-[l-//u< o-2,3-diacetoxy-(l-hydroxypropyl)]-2-phenyl-l,2,3-triazole-5-carboxylic acid lactone (74a) <77CAR(59)141>. Analogous reactions of the derivatives (72) with substituted aryl hydrazines yielded the triazoles (74b-d). Alternatively, the hydrazone oximes (73a-d) may be treated with HBr in... 

Fluorination of Esters of Carboxylic Acids, Lactones, and Related Compounds... 

Hydroxy-5-iodobicyclo [2.2.2] octane-2-carboxylic acid lactone 116 86 30... 

Under these conditions esters, carboxylic acids, lactones, amides, nitriles, alkyl halides, and nilro compounds arc not reduced. Some of the groups are reduced, however, in refluxing 2-cthyHiexanol (I30 ). 

The Ci5 terpenoids known as sesquiterpenoids are the most chemically diverse group of terpenoids known in nature. Like monoterpenoids, many sesquiterpenoids contribute to the flavor and fragrances of a variety of plant products. To date about 10,000 sesquiterpenoids are known (32), and in the plant kingdom they commonly occur as hydrocarbons, alcohols, aldehydes, ketones, carboxylic acids, lactones, and oxiranes. The acyclic sesquiterpene hydrocarbons a- and p-farnesenes (HI and H2, respectively) (Fig. 8) are constituents of the oils... 

Oxidation of the C] aldehyde (hemiacetal) to the carboxylic acid (lactone). 

Hydroxydiphenyl-2-carboxylic acid lactone. Baeyer-Villiger oxidation of 9-fluorenone to 2 -hydroxydiphenyl-2-carboxylic acid lactone is done conveniently in even large-scale runs1 by slow addition with cooling in acetone-dry ice of 55 ml. 

Most of them are esters. They may also be alcohols, carboxylic acids, lactones, aldehydes, ketones, and hydrocarbons (Silverstein, 1984). Crucial properties of releaser pheromones are their volatility, their stability, and, of course, the degree of specificity possible to build into a relatively small molecule. The molecular weight tends to be between 80 and 300. On the basis of evaporation and diffusion rates, it can be predicted that long-distance sex pheromones would have a molecular weight between 200 and 300. A pheromone may be one chemical, but usually it is a mixture of chemicals, each of which is a component of the pheromone. Mixtures increase the specificity, a property important especially for the sex pheromones. 

H 4.26%, O 45.03%. HOOCCH = CHCH=CH-COOH. Prepd by oxidation of phenol and peracetic acid Boeseken. Engelberts, C.A. 26t 2970 (1932) by treatment of ethyl 1,4-dtbromoadipate with alcoholic potassium hydroxide Guha, Sankaran, Org, Syn. 26, 57 (1946) by isomerization of 3-hydroxy-4-carbomethoxybut-1-ene-1-carboxylic acid lactone Elvidge et at, J, Chem, Soc, 1950, 2235 by carbonylation of acetylene Tsuji er al. J. Am. Chem, Soc. 86, 2095 (1964). Configuration and separation of isomers Boeseken, Kerkhoven, Rcc Trav. Chim. Si, 964 (1932) Elvidge et at, J. Chem Soc. 1953, 708. 

Sikkimotoxin, 3a,4,9,9a-Tetrahydro-4-hydroxy-6,7-dunethoxy-9-(3,4,S-trimethoxyphenyt)naphtho 2,3-c -furan-I(3H) >ne 1 -hydroxy-2-hydroxymethyl-6,7-dimeth -oxy-4-(3 4 5 -trim ethoxy phenyl)-1,2,3,4-let rahydro-naphthalene-3-carboxylic acid lactone, C Hj p, mol wt 430.44. C 64.17%, H 6.09%, O 29.74%. Isoln from roots and rhizomes of Podophyllum sikkimeitsis R. Chatterjee et Mukerjee, Berberidaceae Chatterjee. Datta, Indian J. Physiol Allied Set 4, 6l (1950). Structnre Chatterjee. Chakra-varti, J. Am. Pharm. Assoc. Scl Ed. 4l, 415 (1952) Schreier, Helv. Chim. Acta 47, 1529 (1964). 

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