| Abstract: | Double aldols, formally derived from acetic acid and two different aldehydes, as obtained by addition of the enolate of (R,R)-2-(tert-butyl)-6-methyl-1,3-dioxan-4-one ( A ) to various aldehydes, are reduced to triols which are actually substituted chiral ‘tris(hydroxymethyl)methanes’ (see B and 3–8 ). Etherifications of the three OH groups of these triols with functionalized halides (allyl, 4-(silyloxy)but-2-en-l-yl, 4-substituted benzyl) and esterifications with pent-4-enoic and 3,5-dinitrobenzyl chlorides, followed by functional group manipulations, lead to the potential center pieces 14–30 for the construction of chiral dendrimers: the building blocks prepared contain the required ‘spacers’ between the core unit, as well as three vinyl groups, three aryl bromide groups, three alcoholic or phenolic OH groups, three mesylate groups, three ester groups, or six arylamino groups at the terminus of their branches. The new compounds are all obtained on a preparative scale and are fully characterized (including elemental analysis). |
