Total synthesis of haliclamine A, a macrocyclic marine alkaloid related to the key biogenetic intermediate of manzamines
作者:Yoshiki Morimoto、Chiho Yokoe
DOI:10.1016/s0040-4039(97)10368-9
日期:1997.12
The first total synthesis of haliclamine A (1), a macrocyclic marine alkaloid closely related to the key bisdihydropyridine intermediate 3 of the biogenetically unique manzamine family, has been efficiently achieved via stepwise inter- and intramolecular N-alkylations of 3-alkylpyridine derivatives 26 and 28.
A new convergent and unified synthesis of the marine natural alkaloid haliclamine A is described. The synthesis of 3-alkylpyridine monomers 8 and 9 was first achieved from a common thiophene intermediate 5. These syntheses make use of thiophene chemistry and the ability of cyclopropylcarbinols 20 and 21 to rearrange to the homoallylic bromides 22 and 23, respectively. The Zincke procedure for the synthesis of pyridinium salts was then applied to the corresponding amino derivatives 8 and 9 to give efficiently unsymmetrical bis-pyridinium macrocycle 1, whose reduction afforded haliclamine A.
Haliclamines A and B, cytotoxic macrocyclic alkaloids from a sponge of the genus
作者:N. Fusetani、K. Yasumuro、S. Matsunaga、H. Hirota
DOI:10.1016/s0040-4039(01)93381-7
日期:1989.1
Total syntheses of macrocyclic marine alkaloids, haliclamines A and B: A convenient and expeditious assembly of 3-substituted pyridine derivatives with different alkyl chains to the bispyridinium macrocycle
The total syntheses of haliclamines A (1) and B (2), macrocyclic marine alkaloids closely related to the key bisdihydropyridine intermediate 3 of the biogenetically unique manzamine family, have efficiently been achieved via stepwise controlled inter- and intramolecular N-alkylations of 3-alkylpyridine derivatives such as 40 and 41. The general synthetic methodology toward the bispyridinium macrocycle