New Strategies for the Synthesis of Biologically Important Tetrapyrroles. The “B,C + D + A” Approach to Linear Tetrapyrroles
摘要:
Linear tetrapyrroles related to phytochrome (1) were prepared in enantiospecific fashion by a new strategy beginning with ring-B,C synthons of type 19 (bis-iododipyrrins). Rings A and D were elaborated by Pd(0)-mediated coupling of 19a with the appropriate alkyne acid or amide derivatives 9 and 20, followed by intramolecular cyclization (method C: BC + D + A --> ABCD).
An improved synthesis of the C,D-ring pyrromethenone of phytochrome and phytochromobilin
作者:Peter A Jacobi、Jiasheng Guo、Sheila I Hauck、Sam H Leung
DOI:10.1016/0040-4039(96)01317-2
日期:1996.8
Pyrromethenone 1b, the C,D-ring segment of both phytochrome (Pr) and phytochromobilin (PΦB) has been prepared in a highly efficient fashion beginning with 2-acetyl-butyrolactone (8). The key steps involved conversion of 8 to the Z-enol triflate 9, followed by Pdo catalyzed coupling with trimethylsilylacetylene, p-chlorophenylselenide ring opening, and amidation, to afford ring-D synthon 11 having the