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91.
A study of the microbiological reduction of different α-halogenoketones (4-chloro-3-octanone, 4-chloro-5-nonanone, 5-bromo-4-nonanone and 5-chloro-4-nonanone) with several strains of microorganism showed great difficulty in reducing ketone functions located in the middle of carbon chains. However, by choosing the appropriate microorganism, several enantiomerically pure diastereoisomers of the corresponding halohydrins have been obtained and were transformed into chiral epoxides. 相似文献
92.
Henri Faure 《Journal of Number Theory》1983,16(3):376-394
We get the asymptotic behaviour of the remainder function with respect to the Van Der Corput generalized sequences construted in a previous paper (in Bulletin de la S.M.F, no 109, 1981). As a consequence, we obtain the intervals [0, a] for which the remainder is bounded. Moreover, we give an explicit formula for the remainder with respect to the Van Der Corput sequence in the r-adic system. 相似文献
93.
94.
Catecholamine levels in body fluids are reliable biochemical markers of several types of tumors, cardiovascular diseases and hereditary and metabolic disorders. Reversed-phase liquid chromatography with electrochemical detection (RPLC-EC) is now the method of choice for catecholamine analysis. 相似文献
95.
96.
The synthesis of three lipophilic n-dodecyl tetraazacycloalkanes is described. Extraction of Cu(II), Cd(II) and Pb(II) is related. 相似文献
97.
Ionic and radical mechanistic steps are postulated in order to explain the formation of the rearrangement-, the isomerization- and the fragmentation-products isolated during the thermal treatment of pyrazolo-diazepines. 相似文献
98.
We propose a new type of optical filter for character recognition. We intend to show that a unique optimized filter is suitable for binary transcoding of an alphabetical set. The unique filtering consists of a multiplexing from a superposition of holographic filters. Synthesis can be implemented either by analog holography or by numerical holography. A verification obtained from a limited alphabet is presented. 相似文献
99.
Vicinal benzoyloxy-trans-bicyclo [2.2.1] heptanic bromhydrins, otherwise difficult to obtain are formed from N-bromosuccinimide and norbornanes bearing a 2-aryl-1,3 dioxolane skeleton. The greater stability of the intermediate dioxolenium ion reduces the tendency towards both Wagner-Meerwein rearrangement and neighbouring group participation by chlorine, processes usually observed when a less stable intermediate is involved. Nevertheless, methoxycarbonyl neighbouring group participation and Wagner Meerwein rearrangment occur in methoxycarbonylbicyclo [2.2.1]heptane and in a bornanic compound respectively. 相似文献
100.