| abstract |
The present invention is directed to methods of forming esters of tertiary alcohols. The methods include reacting a compound containing a tertiary alcohol with an acyl heteroaromatic ion-based compound of the formula:whereinR1 is an aromatic or aliphatic acid residue;Y is O or S;Z is CR2 or N;X is selected from the group consisting ofwherein R2 and R3 are independently selected from the group consisting of H, C1-6 alkyls, C1-6 substituted alkyls, C1-6 heteroalkyls, C3-8 branched alkyls, C3-8 cycloalkyls, C1-6 substituted heteroalkyls, aryls, substituted aryls, C1-6 alkyl aralkyls, C1-6 heteroalkyl aralkyls, C3-8 branched alkyl aralkyls and C3-8 cycloalkyl aralkyls; and R2' is the same as R2 except that R2' is not H;in the presence of a lanthanideIII metal-based catalyst and a base. In preferred embodiments, a substantially pure optical isomer of a compound containing a tertiary alcohol is used and the resultant esters are of sufficient purity so that expensive and time consuming recrystallization or purification steps are avoided. |