Lactone epoxidation

Zheng J. Screening of active anti-inflammatory, immunosuppressive and anti-fertility components of Tripterygium wildfordii III. A comparison of the anti-inflammatory and immunosuppressive activities of 7 diterpene lactones epoxides compounds in vivo. Zhongguo Yixue Kexueyuan Xuebao 1991 13 391-397. 

The terminal carhanionic sites of "living" polymers can be reacted with various electrophilic compounds of yield (o)-functional polymers. Esters, nitriles, acid chlorides, anhydrides, lactones, epoxides, benzyl or allyl halogenides have been used for their high reactivity with metal organic sites, to yield appropriate functions.2 Carbon dioxide is also an efficient reagent to yield terminal carboxylic functions. 

The synthesis of arene oxides 44, 46, and 47 via cyclohexane bromo-j3-lactone epoxide intermediates constitutes a novel synthetic approach to arene 2,3-oxides.Although the final consecutive dehydrobromination and thermal decarboxylation steps in the synthesis of 44,46, and 47 proceed under mild conditions, they do not, however, permit the isolation of 1 from the corresponding bromo- 3-lactone epoxide. 

Oja-Dichloro-y-lactones Epoxides such as styrene oxide undergo C-O bond insertion with dichloroketene generated in situ. 

Borohydride-reduced palladium. Reduction of palladium chloride in methanol with sodium borohydride until evolution of a gas ceases leads to a black material, which is not particularly sensitive to air and is not pyrophoric. The material is useful for selective hydrogenations. It catalyzes rapid hydrogenation of bonds of the type C=C, N=N, and N=0, but not the type C=N and C=0. Nohydrogenolysisof nitrogen or oxygen functions is observed in alcohols, amines, amides, esters, ethers, or lactones. Epoxides are opened to alcohols very slowly. 

In the past 20 years hundreds of Chinese traditional and herbal medicines with immunomodulating functions have been screened, and their active components studied. Through these studies, six diterpene lactone epoxide compounds, with antiinflammatory and immunosuppressive actions, were isolated from T. wilfordii. Zheng et al. [183] assayed the half-effective dose (ED50), the therapeutic index (TI) and a certain safety factor (CSF) using croton oil induced ear swelling and hemolysin-antibody formation mouse models and found that triptolide (79), tripdiolide (80), triptonide (81), tripchlorolide (92), and triptolidenol (93) possessed both antiinflammatory and immunosuppressive activities, while triptriolide (94) showed antiinflammatory action only. Fig. (28). The results of the TI and CSF of both activities clearly demonstrated that the antiinflammatory and immunosuppressive compounds in T. wilfordii are pluralistic and the differences in these compounds can be used as a base for the evaluation and selection of them. 

Uses Reducing agent for aldehydes, ketones, acid chlorides, lactones, epoxides, and esters source of hydrogen and borohydrides Manuf./Distrib. Alfa Aesar http //www.alfa.com, Chemetall Chem. Prods. http //www. chemetall. com Lithium bromide... 

PhLi/Te or Ph2Te2/Na with Me SiCl, and ring opens lactones, epoxides... 

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