THE BIRCH REDUCTION OF 3-SUBSTITUTED PYRROLES

The Birch reduction of electron-deficient 3-substituted pyrroles is de scribed. Use of a reductive alkylation procedure involving sodium meta l in liquid ammonia gave good yields of 4-alkyl-2-pyrrolines. The iden tity of these products was proven by an X-ray structure of a crystalli ne derivative. Moreover, the pyrroles used in this study could be read ily prepared by reaction of TOSMIC with acrylic amides and esters and, once the reduction was complete, the ester activating group could be easily removed to yield the corresponding N-protected beta-proline der ivatives. (C) 1998 Elsevier Science Ltd. All rights reserved.