Toward the Synthesis of Biologically Important Chlorins, Isobacteriochlorins, and Corrins. Cyclic Enamides from Acetylenic Amides
摘要:
Cyclic enamides 1 of a type useful in the synthesis of naturally occurring chlorins, isobacteriochlorins, and corrins have been prepared by a process involving 5-exo-dig cyclization of the appropriate acetylenic amides 11. The desired cyclization is catalyzed by either n-Bu(4)NF or LiAl-(NHBn)(4).