An Easy Access to Two Epimeric N - Substituted ( 2 S ) - 2 - ( 2 ́ - Hydroxypropyl ) pyrrolidines

There are entries for the racemic alcohols 3 and 4, and also of enantiomerically pure 4. Our interest developed knowing the fact that pyrrolidine derivatives possess biological activities. For obtaining the aforementioned alcohols, our first approach was to prepare ketones 5a and 6 in the enantiomerically pure forms. In fact racemic 5 was prepared earlier in four steps by a tandem S N 2-Michael addition reaction without any description about their optical purity. Racemic 6 is also known. This contribution therefore gives a detailed account of acquiring compounds 1a, 2a, 3, 4, 5a and 6 starting from (S)-prolinol 7 or (S)-proline 15 (Schemes 1 and 3).