Macrocyclic ester

Despite this considerable literature noted above, it was really Bradshaw and coworkers who pioneered the synthesis of macrocyclic ester analogs of crown ethers "... 

Okahara and his coworkers have made a number of contributions to the synthesis of crown ethers using a one-pot method (see Sect. 3.13). These methods have been applied largely to the preparation of simple aliphatic crown ether systems. In addition, this group has prepared macrocyclic ester compounds using a one-pot procedure. Although... 

Table 5.9. Macrocyclic esters of furan-2,5-dicarboxylic acid...

Table 5.11. Macrocyclic esters containing the 3,5-dipicolinate subunit...

The macrocyclic esters hold a special position among the industrially produced lactone fragrance materials. Like the well-known macrocyclic ketones, they have outstanding odor properties as musks. However, the lactones can be prepared more easily than the ketones, for example, by depolymerization of the corresponding linear polyesters. Since replacement of a methylene unit by oxygen affects the odor of these compounds very little, oxalactones with 15-17-membered rings... 

Zhang, D., Hillmyer, M.A. and Tolman, W.B. 2004. A New Synthetic Route to Poly[3-Hydroxypropionic Acid] (P[3-HP]) Ring-Opening Polymerization of 3-HP Macrocyclic Esters. Macromol., 37, 8198-8200. 

Table 1 Selected macrocyclic esters and their corresponding mass spectral data. Esters were converted into hepatitis C antiviral agents after amidation with selected Intermediate Amines illustrated in Table 3...

Table 3 Intermediate Amines used in coupling with selected Step 6 macrocyclic ester intermediate...

Macrocyclic esters of bismuth(m) and bismuth(v) acids and thioacids 972... 

Macrocyclic esters were prepared according to the method of Brunelle [1], which cyclo-oligomerizes terephthaloyl chloride and 1,4-butanediol with triethylamine dissolved in CH2CI2. 

Kuhlman [5] re-polymerized macrocyclic ester oligomers in the presence of di-n-butyl tin oxalate, which had up to a 2 minute latency period and was followed by a rapid polymerization similar to that of di-n-butyltin glycolate. 

Several species of Fusarium infect com, wheat, barley, and rice. Under favorable conditions they elaborate a number of different types of tetracyclic sesquiterpenoid mycotoxins that are composed of the epoxytrichothecene skeleton and an olefinic bond with different side chain substitutions (fig. 9). Based on the presence of a macrocyclic ester or ester-ether bridge between C-4 and C-15, trichothecenes are generally classified as macrocyclic (type C) or nonmacrocyclic (types A and B) (table 5). Other fungal genera producing trichothecenes are Myrothecium, Trichoderma, Trichothecium, Acremonium, Verticimonosporium and Stachybotrys. The term trichothecenes is derived from trichothecin, the first compound isolated in this group [115, 147-153]. 

ArsBi bearing ortho methoxy groups mediates dehydrative condensation of a-monosubstituted carboxylic acids with alcohols and amines (Scheme 14.139) [288]. Macrocyclic esters can be synthesized by the ArsBi-templated reaction of diols with dicarboxylic acid derivatives [289]. The Bi-C bonds of Ar Bi are cleaved by diphenyl diselenide and ditelluride to give aryl phenyl selenides and tellurides, respectively (Scheme 14.140) [290]. The reaction of ArsBi with elemental chalcogen (E Se, Te) affords a mixture of the respective dichalcogenides (ArEEAr) and monochalcogenides (ArEAr). 

The pigments of the Fusaria have been described in Chapter 7. Many of the characteristic phytotoxic metabolites are the sesquiterpenoid trichothecenes (8.38) (see Chapter 5). The more highly hydroxylated members have considerable mammalian toxicity as well as phytotoxicity. Trichothecenes have been identified as metabolites of species from ten of the twelve sections of the genus Fusarium as classified by Booth. The trichothecenes occur with various combinations of oxygen substituents at positions 3, 4, 7, 8 and 15. Several trichothecenes contain macrocyclic esters linking C-4 and C-15. These are known as the roridins and verrucarins. 

Trichothecenes are characteristic metabolites of Fusarium species and have been isolated from species belonging to ten of the twelve sections of the genus Fusarium as classified by Booth. The majority contain a 12,13-epoxide and a C-9 C-10 double bond and occur with various combinations of additional oxygen substituents at positions C-3, C-4, C-7, C-8 and C-15. Many of the hydroxyl groups are esterified and there are several macrocyclic esters known as the verrucarins and roridins in which the esters link C-4 and C-15. 

R Macrocyclic ester or ester-ether bridge between carbons 4 and 15. The most abundant macrocyclic trichothecenes are verrucarins, roridins, and satratoxin H. Source for this statement Jarvis BB. Macrocyclic trichothecenes. In Sharma RP, Salunkhe DK, eds. Mycotoxins and Phytoalexins. Boca Raton, Fla CRC Press 1991 361-421. 

Chojinowski, J., Scibiorek, M., and Kowalski, J., Mechanism of the Formation of Macrocycles During the Cation Polymerization of Cyclotrisiloxanes. End to End Ring Closure Versus Ring Expansion, Makromol. Chem., 178,1351,1977. Spanagel, E.W. and Carothers, W.H., Macrocyclic Esters, /. Am. Chem. Soc., 57, 929, 1935. 

---