Lithium triethyl borohydride reduction with

Double bonds of benzene and related aromatic compounds do not react with diazoalkanes in 1,3-cycloadditions. The corresponding benzo-annellated dihydro-pyrazoles such as (1 a,6a)-6,9,9-trimethyl-7,8-diazabicyclo[4.3.0]nona-2,5,7-triene (6.98, R = H) can be synthesized, however, from methyl cyclohexa-l,4-dienecarboxy-late (6.97, R = H), as shown by Klarner et al. (1990). The reduction of the ester group to a methyl group was carried out with di-isobutylaluminum hydride (DIBAL-H), esterification of the OH group with methanesulfonyl chloride and reduction with lithium triethyl borohydride. The second double bond was introduced by bromina-tion with Br2 on a polymeric carrier after Bongini et al. (1980). Cycloaddition with 2-diazopropane in ether at -- 5 °C and the following steps gave 6.98 in a yield of 58%. 

Two approaches for the synthesis of nanostructured M50 type steel (composed of 4.0% Cr, 4.5% Mo, 1.0% V, 0.8% C and balance Fe) powders and their consolidation are reported in this chapter. One approach involved the sonochemical decomposition of organometallic precursors and the other involved the reduction of the metal halides with lithium triethyl borohydride followed by vaccum sublimation of the powders to remove lithium chloride. The as-synthesized powders are amorphous by X-ray diffraction (XRD) but the peaks corresponding to bcc a-Fe are observed in the compacts. The morphology and composition of the powders synthesized by both techniques, as well as the compacts, were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Hardness, density, particle size and impurity contents were also determined for the compacts. In addition, pure nanosized iron particles obtained by the ultrasound decompositon of iron pentacarbonyl were consolidated and the properties of the latter were studied. 

Preparation.—The reduction of elemental sulphur with lithium triethyl-borohydride in THF using appropriate stoicheiometries is known to produce... 

The cyclic anhydride was converted into the amide acid which on Hofmann rearrangement followed by lithium borohydride reduction on the ester gave a derivative of ip-amino-2a, 3a-dihydroxy-43-hydroxy-methylcyclopentane. Condensation of the amino-triol with 5-amino-4,6-dichloropyrimidine followed by ring closure with triethyl orthoformate gave the 6-chloropurine derivative which on treatment with ammonia gave 11. ... 

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