Total synthesis of a cytotoxic acetogenin, pyranicin.
[structure: see text] The first total synthesis of a new cytotoxic acetogenin, pyranicin (1), is described. SmI(2)-induced reductive cyclization of beta-alkoxy acrylate 4 proceeded stereoselectively to give 16,20-syn-19,20-trans-THP derivative 14, which was efficiently transformed into the 19,20-cis-THP derivative 18 through Mitsunobu lactonization. Wittig reaction of the phosphonium salt 2 obtained therefrom with butenolide 3 at -78 degrees C followed by reduction and deprotection afforded 1 in good overall yield.
Takahashi
Shunya
S
RIKEN-The Institute of Physical and Chemical Research, Wako, Saitama 351-0198, Japan. shunyat@postman.riken.go.jp
Kubota
Akemi
A
Nakata
Tadashi
T
D029061:Annonaceae / Q000737:chemistry; D000890:Anti-Infective Agents / Q000138:chemical synthesis; D000972:Antineoplastic Agents, Phytogenic / Q000138:chemical synthesis; D005663:Furans / Q000138:chemical synthesis*; D007783:Lactones / Q000138:chemical synthesis*
D000890:Anti-Infective Agents; D000972:Antineoplastic Agents, Phytogenic; D005663:Furans; D007783:Lactones; C475590:pyranicin