Fert-Butyl hydroperoxide

Although it was also Henbest who reported as early as 1965 the first asymmetric epoxidation by using a chiral peracid, without doubt, one of the methods of enantioselective synthesis most frequently used in the past few years has been the "asymmetric epoxidation" reported in 1980 by K.B. Sharpless [3] which meets almost all the requirements for being an "ideal" reaction. That is to say, complete stereofacial selectivities are achieved under catalytic conditions and working at the multigram scale. The method, which is summarised in Fig. 10.1, involves the titanium (IV)-catalysed epoxidation of allylic alcohols in the presence of tartaric esters as chiral ligands. The reagents for this asyimnetric epoxidation of primary allylic alcohols are L-(+)- or D-(-)-diethyl (DET) or diisopropyl (DIPT) tartrate,27 titanium tetraisopropoxide and water free solutions of fert-butyl hydroperoxide. The natural and unnatural diethyl tartrates, as well as titanium tetraisopropoxide are commercially available, and the required water-free solution of tert-bnty hydroperoxide is easily prepared from the commercially available isooctane solutions. 

I. 463 A) is close to the value for fert-butyl hydroperoxide (1) (95° and 104°, two crystallo-graphically independent molecules), which points to a comparatively small steric demand of the acyl group in peresters. Due to its structural similarity to diaUsyl peroxides, it is reasonable that the ortho ester 56 P2, 0—0 = 1.481 A, C—O—O—C = 145.1°) exhibits a significantly larger peroxide dihedral angle than 54 . 

The liquid enthalpy of formation difference between 1-hexyl and 1-heptyl hydroperoxides is almost twice that of a normal enthalpy of formation methylene increment of about 25 kJmol . But which of these two, if either, is correct For hydrocarbon snb-stituents bonded to electronegative functional groups, the secondary isomers are more stable than the n-isomer. Accordingly, either the 1- or 4-heptyl hydroperoxide, or both, have an inaccurate enthalpy of formation because the primary isomer is reported to have the more negative enthalpy of formation. All of the enthalpies of formation for the Cg and C7 hydroperoxides cited in Reference 2 come from a single source. There is a reported value for the gas phase enthalpy of formation of fert-butyl hydroperoxide that is 11 kJ mol less negative than the value in Reference 2. 

The value is from the liquid phase enthalpy of reaction between cyclohexanone and fert-butyl hydroperoxide from V. L. Antonovskii, E. V. Federova, N. E. Shtivel and V. D. Emelin, Kinet. Katal., 30, 1235 (1989). 

The Wang group also reported the asymmetric epoxidation of chalcone derivatives with their polymer-supported dimeric PTC 61 using fert-butyl hydroperoxide as an oxidant (Scheme 4.18) [23]. 

The author thanks D. R. Mosely for assistance with the experimental work, V. J. Zichy for the infrared spectra determinations, A. R. Jeffs for the vapor phase chromatographic analysis, D. G. Corbin for the purification of fert-butyl hydroperoxide, and R. J. Hurlock for the preparation of dilauryl sulfinyl dipropionate. 

Wang, C.J., Wang, J.M., Lin, W.L., Chu, C.Y., Chou, RP, and Tseng, T.H., Protective effect of Hibiscus anthocyanins against fert-butyl hydroperoxide-induced hepatic toxicity in rats. Food Chem. Toxicol., 38, 411 16, 2000. 

Enone 13 was epoxidized with fert-butyl hydroperoxide in tetrahydrofuran in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) at room temperature to give epoxide 14 in 95 % yield. The epoxide was further converted into (-)-tirandamycin A73. 

Other peroxides such as fert-butyl hydroperoxide [226, 227], performic acid 247, 248], peroxytrifluoroacetic acid [/55], peroxydichloromaleic acid [339], and dimethyldioxirane [210] are used less frequently. 

During the enantioselective total synthesis of miroestrol by E.J. Corey and co-workers, the introduction of a hydroxyl group was required at one of the bridgehead positions. This position was a to a ketone and was also the allylic position to a double bond. The oxidation was effected by selenium dioxide/fert-butyl hydroperoxide at 25 °C. 

Co(salen)-catalyzed oxidation of phenols with fert-butyl hydroperoxide in CH2CI2 at room temperature provides predominantly tert-butylperoxylated products . On catalytic oxidation of 2,6-di(tert-butyl)-4-acetylphenol oxime O-methyl ether (261), both o- and p-(ferf-butylperoxy)quinol ethers (262 and 263) were obtained in 8.1 and 87.3% yields, respectively. On the other hand, catalytic oxidation of 264 provided the corresponding o- and p-quinol ethers (265 and 266) in 91.1 and 6.8% yields, respectively (Scheme 56). The remarkable difference of the o/p ratio in the reactions of 261 and 264 reflects clearly a combination of both steric and electronic factors. 

P. Wadhwani, M. Mukherjee, D. Bandyopadhyay, The prime reactive intermediate in the iron(III) porphyrin complex catalyzed oxidation reactions by fert-butyl hydroperoxide, J. Am. Chem. Soc. 123 (2001) 12430. 

Osmate esters are fairly stable but are readily cleaved in the presence of an oxidizing agent such as fert-butyl hydroperoxide. 

Biosynthesis of the polycychc diterpene intricarene (144) may occur from the natural product bipinnatin J (141) through transannular [5 - - 2] cycloaddition reaction. Based upon this proposed biosynthetic route, Tang et al. examined a synthesis of 144 [45]. Synthetic 141 was treated with VO(acac)2 and fert-butyl hydroperoxide, followed by acetic anhydride to give acetoxypyranone 142, which was subsequently heated in acetonitrile in the presence of DBU to give intricarene (144) (Scheme 7.32). 

Twenty drops of 60% fert-butyl hydroperoxide (approximately 0.012 gm/drop) is added to a solution of 8.0 gm of diallyldiethylammonium... 

The selective functionalization of saturated hydrocarbons is an important and challenging academic and industrial objective. Our own contributions to this area are based on Gif-type systems. Recent studies have shown that fert-butyl hydroperoxide (TBHP) is an efficient oxidizing agent in these systems. 

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