A thorough investigation of the use of organic soluble lanthanide complexes as catalysts in Diels-Alder reactions was undertaken. Eu(fod)(,3) was shown to be an excellent catalyst for the hetero Diels-Alder reaction between aldehydes and highly oxygenated dienes. With most dienes, the reaction exhibited high endo topological control and has already found widespread use in organic synthesis.

The chiral lanthanide complex Eu(hfc)(,3) was also shown to catalyze the hetero Diels-Alder reaction and in some cases was able to induce enantiofacial selectivities up to 58% ee. Interestingly, the combination of chiral dienes with the chiral catalyst did not, in many cases, follow the rules of simple double diastereoselectivity. Instead, only combinations between dienes whose inherent face selectivities were small and opposite to that of the (+)Eu(hfc)(,3) catalyst were able to achieve substantial asymmetric inductions (de's 95%). An empirical model was given to account for this seemingly strange behavior. It was concluded that in addition to the well-known processes of substrate control, reagent control and double diastereoselectivity, a third possibility called "intimate substrate-catalyst interactivity" existed which could account for these results.

The usefulness of the chiral catalyst-chiral diene system was demonstrated by the total synthesis of L-glucose, L-glucuronic acid, 4-deoxy-L-glucose and a variety of L-glucals from non carbohydrate precursors. Also, model studies toward the synthesis of glycolipids, dissaccharides and the aminocyclitol antibiotic spectinomycin were completed demonstrating the viability of this method as an alternative to standard glycosylation procedures.

Finally, lanthanide catalysis was also evaluated for its possible use in both the inverse demand and homo type Diels-Alder reactions. In these cases, dienophiles and dienes were chosen which under either thermal conditions or conventional Lewis acid catalysis fail to react or give poor stereoselectivity. Yb(fob)(,3) was shown to be an excellent catalyst for both of these reactions. Cycloaddition occurs between crotonaldehyde and ethyl vinyl ether in an inverse demand Diels-Alder reaction under the influence of Yb(fod)(,3) to give a 64% yield of one adduct derived from an endo topological transition state. In addition, acrolein reacts with furan in a homo Diels-Alder reaction to give predominantly the exo 7-oxo-bicycloheptane in good yield. Interestingly, this product is derived from an exo transition state. Unfortunately, the chiral catalyst Eu(hfc)(,3) produced only trace amounts of optical induction in these reactions ((DBLTURN)10% ee).