A new protocol of protection of poorly reactive aryl amines and functionalized amines with Boc 2 O in the presence of Zn(ClO 4 ) 2 •6H 2 O as the catalyst is reported. The catalytic action of Zn(ClO 4 ) 2 •6H 2 O is specific for the activation of the pyrocarbonates, thus acid sensitive functionalities and stereochemical configurations of the starting materials remain unaltered in the protection process.

The synthetic potentialities of cerium(III) chloride are demonstrated by the synthesis of a nine-membered ring heterocycle component of Griseoviridin (3) in optically active form. The key step involves the stereospecific formation of the alpha-carbalkoxy alkenyl sulfide moiety using a combination system of cerium(III) chloride heptahydrate and sodium iodide.

[reaction: see text] The first asymmetric aminolysis of trans-aromatic epoxides with anilines is described. The process affords enantioenriched anti-beta-amino alcohols in up to 99% ee. The complete regio- and diastereoselectivity observed uses commercially available [Cr(Salen)Cl] as a Lewis acid catalyst and in combination with a very simple experimental procedure renders the present reaction a facile and practical tool for the synthesis of chiral nonracemic anti-beta-amino alcohols.

A trace amount of magnesium perchlorate (from 0.1 mol% to 1 mol%) is able to promote quantitative acylation, with anhydrides, of a large variety of functionalized alcohols in short times, at room temperature and under solvent-free conditions.

Zinc perchlorate hexahydrate, Zn(ClO 4 ) 2 · 6 H 2 O, efficiently catalyses the esterification between nearly equimolar amounts of carboxylic acids and alcohols. The reaction works under solvent-free conditions at relatively low temperatures. Excellent results were obtained with a wide range of substrates.