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A series of new hydroxamic acid derivatives (VI) (6 examples) are designed, synthesized, and evaluated for their in vitro antibacterial and antiproliferative activities.

Conjugate addition of nitromethane to 2-arylidene-1-tetralones anchored on Cr(CO) 3 was found to be about 100% stereoselective.

Cyclopropanation of 2-arylidene-1-tetralone tricarbonylchromium complexes with dimethylsulfoxonium methylide under phase-transfer catalysis condition provided cyclopropanes exclusively from the endo-face.

Stereoselective annulations on Cr(CO)3 complexed tetralone and benzosuberone§ derivatives have been achieved. Diastereomeric products are shown to be related by an epimerisable chiral centre. An unusually facile de-ethoxycarbonylation has been observed.

In arene–tricarbonylchromium complexes, exo-selectivity is the normal. This account, on the other hand, summarizes our results of endo-selective nucleophilic additions with very high stereocontrol at relatively remote sites, which enhances the potential of these complexes as synthons for target synthesis.

Efficient diastereocontrol is achieved in Hosomi-Sakurai reaction of flexible acyclic enones anchored on arene­ tricarbonylchromium template. Relative stereochemistry of groups in the products is compared with those obtained by al­ lylmagnesium bromide addition followed by an anionic oxy-Cope rearrangement. The results indicate an endo-selective conjugate addition dictated by an out-of-plane bound Lewis acid in the Hosomi-Sakurai reaction, similar to the trend estab­ lished earlier for rigid substrate structures. We recently reported I an unusual , endo-selective, conjugate allylation on 2-arylidene-1-tetralone tricar­ bonylchromium complex 2 by Hosomi-Sakurai reac­ tion 3 . In this stereochemically well-defined substrate, the expected in-plane coordination of Lewis acid to the ketone carbonyl group was thought to be pre­ vented by two flanking hydrogens, the peri proton of the aromatic ring of tetralone and the l3-olefinic pro­ ton, held in a rigid framework. As a result, the Lewis acid was forced to coordinate in an out-of-plane man­ ner from the more accessible exo face, which in tum blocked approach of reagent from the same face. The net effect was an endo-selective allylation (Scheme I). The same concept was subsequently ex­ ploited to predictably induce endo-selective nucleo­ philic additions of organolithium 4 and organomagne­ sium 5 reagents to such substrates in presence of Lewis acids. In flexible, acyclic analogues, a rotation about the C(O)-alkene bond leading to cisoid (I and II) or tran­ soid (III) orientation of the enone (Chart 1) can jeop­ ardize diastereoselectivity. It may be noted, however, that the steric inhibition offered by the flanking hy­ drogens in I or II (cisoid orientation) would still ad