Development of Efficient Chiral Synthetic Process of Bioactive Compounds.

(1)通过环二烯与2-恶唑酮和2-咪唑酮的[4，2]环加成反应，合成了空间密集的2-恶唑烷酮和2-咪唑烷酮对映体，作为高效的手性助剂。揭示了这些助剂在烷基化、Diels-Alder反应、Michael反应和Aldol反应等不对称合成反应中的应用。(2)将2-恶唑烷酮类化合物水解成具有合成意义的构象固定的2-氨基醇。氨基醇的N-磺酰基衍生物的锂盐因此获得了几乎完全非对映选择性的裂解中位二元酸酐的半酯。相反，锌盐与酸酐的反应具有相反的选择性。2.对映体选择性方法的发展2-恶唑烷酮环裂解制得的N，N-二烷基氨基醇和N-磺酰氨基醇在醛与ZNET_2的乙基化反应中同样有效，但有趣的是表现出完全相反的对映选择性。

1.Development of Diastereoselective Procedures.(1) Both enantiomers of sterically congested 2-oxazolidinones and 2-imidazolidinones, which served as efficient chiral auxiliaries, were synthesized by [4+2] cycloaddition of cyclic dienes with 2-oxazolone and 2-imidazolone. The utilities of these auxiliaries in asymmetric synthetic reactions such as alkylations, the Diels-Alder reactions, Michael reactions and aldol reactions were revealed.(2) The 2-oxazolidinones were hydrolyzed to conformationally fixed 2-amino alcohols of synthetic significance. The lithium salts of N-sulfonyl derivative of amino alcohols thus obtained cleaved meso-dicarboxylic anhydrides to the half esters with almost perfect diastereoselectivity. In contrast, zinc salts reacted with the anhydrides with opposite selectivity.2.Development of Enantioselective Procedures.N,N-Dialkylamino alcohols and N-sulfonylamino alcohols which were derived from ringcleavage of the 2-oxazolidinones served as equally effective catalysts in ethylation of aldehydes with ZnEt_2, but interestingly showed completely reversed enantioselectivity.