Studies On The Synthesis Of Long-chain Alkyl Proline Derivatives And Their Stereoselectivity In Aldol Reaction

In this thesis, two long-chain alliyl proline derivatives 1a and 1b were synthesized from readily available trans-4-hydroxy-L-proline. The catalytic activity and enantioselectivety of la and lb in the Aldol condensation of aromatic aldehydes and acetone were studied in organic phase or aqueous phase. Synthesis of long-chain aminated proline derivatives was preliminary studied.â… . Two long-chain alkyl proline derivatives 1a and 1b were synthesized from readily available trans-4-hydroxy-L-proline through the two synthetic routes. All eight kinds of novel intermediate products and two targete products were characterized respectively by IR, ¹HNMR, ¹³CNMR, HRMS, etc. Compound 1b was further characterized by X-ray diffraction.One:â…¡. Synthesis of long-chain aminated proline derivatives was preliminary studied. But the rate of conversion was very low in the process of amination. The searches of the optimal conditions of the amination and the study of their catalytic behavior for Aldol reaction are now underway.HO.â…¢. The catalytic activity and enantioselectivety of la in the Aldol reaction have been studied in organic phase in the influence of different solvent, temperature and the amount of catalyst etc. The results indicated that when only 3mol% of la was used , both the activities and selectivities were similar to 20mol% of la in acetone(The amount ofL-proline is about 20mol% in DMSO in the literature). The enantioselectivity of the reaction in organic solvents is normally increased at lower reaction temperature. The catalyst also shows expanded solvent scope.OHla, 3mol%Acetone, r. t.,24h82.4%yield, 57.2%eeIV. The catalytic activity and enantioselectivity of la in the Aldol condensation were studied in aqueous phase in the influence of temperature and the amount of catalyst. In water, both the yield and ee value of the Aldol condensation of nitro- benzaldehydes and acetone were about 50%. The catalytic activity and enantio- selectivity of la was strongly dependent upon the reaction temperature and the amount of the catalyst. A plausible mechanism for the catalyzation in water was proposed and discussed. The long-chain alkyl derivatives of L-proline may form some kindes of chiral micelle systems in water by its self aggragation, by which the Aldol reaction were accelerated on the interface of the micelle through a mutual effect.OH20mol%la 63.9%yield, 44. l%ee 10 mol%la 53.4%yield, 54.5%ee 5 mol%la 46.2%yield, 62.4%ee...