Regio- and Stereoselective Addition of HO/OOH to Allylic Alcohols.

A range of allylic alcohols are shown to readily react with ethereal H2O2 in the presence of catalytic amounts of Na2MoO4-gly or MoO2(acac)2, affording the C═C trans hydroxylation-hydroperoxylation products in good yields with high regio- and stereoselectivity. Use of enantiomers of cyclic substrates resulted in corresponding enantiopure diol-tert-hydroperoxides. The possibility of further conversion of the diol-tert-hydroperoxides into triols or linear building blocks with an isolated tert-peroxy group containing a quaternary center is also exemplified.

A Low-Cost and Scalable Synthesis of a Cyclohexanone-Related Bifunctional Building Block.

A practical route to 2-(2-(2-methyl-1,3-dioxolan-2-yl)ethyl)cyclohexan-1-one was developed, featuring the use of inexpensive starting materials/reagents and readily attainable reaction conditions. The overall transformation was achieved in 53% yield with one chromatographic purification via NaOH-mediated aldol condensation, ethylene glycol protection of the ketone group in the presence of HC(OEt)3/concd HCl, saturation of the C=C bond and the benzene ring with Al-Ni alloy in aqueous KOH, and oxidation of the intermediate cyclohexanol with aqueous NaClO/TEMPO/KBr.

[Near-infrared reflectance spectroscopy analytic models established for the crude protein and crude fiber of alfalfa property].

Near-infrared reflectance spectroscopy (NIRS) calibrations of crude protein and crude fiber in 152 alfalfa samples were developed by means of partial least-squares (PLS) regression. Different interval wavelengths of 1, 2 and 5 nm and two kinds of samples (crude and fine) were set to collect spectral data and establish calibration respectively. The accuracy and repeatability of calibrations were verified so as to compare superiority and inferiority. Results showed that the best validation result is the calibration by 2 nm interval wavelength and fine sample, and the correlation coefficients of calibration (R2) were 0.97 and 0.94 for crude protein and crude fiber, and the SECV of these parameters were 0.42 and 0.78 respectively. The coefficients of determination for validation (R2(val)) were 0.96 and 0.92, and the SEP of these parameters were 0.43 and 0.79. The experiment showed that it is feasible to evaluate the major quality traits of alfalfa by NIRS. All together, it provided a new model to verify the crude protein and fiber compositions of alfalfa.

Facile perhydrolysis of oxetanes catalyzed by molybdenum species.

Perhydrolysis of a range of tertiary oxetanes was achieved in synthetically useful yields under mild conditions. Different functional/protecting groups were tolerated. Similar ring-opening of secondary oxetanes, which had been unfeasible to date, was also realized with ease. With the aid of optically active substrates the perhydrolysis was shown to proceed with significant stereoselectivity.

A hydrogen peroxide based access to qinghaosu (artemisinin).

Attachment of H(2)O(2) onto the highly hindered quaternary C-12a in an advanced qinghaosu (artemisinin) precursor has been achieved through a facile perhydrolysis of a spiro epoxy ring with the aid of a previously unknown molybdenum species without involving any special equipment or complicated operations. The resultant ß-hydroxyhydroperoxide can be further elaborated into qinghaosu, illustrating an entry fundamentally different from the existing ones to this outstanding natural product of great importance in malaria chemotherapy.