Total synthesis of the marine sesquiterpenes dactylol and africanol. De novo construction of a cyclooctanoid natural product from cycloheptane precursors
Conformationally selective transannular cyclizations of humulene 9,10-epoxide. Synthesis of the two skeletally different cyclohumulanoids: dl-bicyclohumulenone and dl-africanol
Twocyclohumulanoids, dl-bicyclohumulenone () and dl-africanol ( were synthesized through newly developed conformationallyselectivetransannularcyclization of humulene9,10-epoxide (). The epoxide was converted to a bicyclohumulenediol diacetate in 70% yield by treatment with BF3·OEt2-Ac2O, while treatment of with trimethylsilyl trifluoromethansulfonate gave an africen-10-ol (a and b) in 80% yield
Sugimura, Takashi; Futagawa, Tohru; Tai, Akira, Chemistry Letters, 1990, # 12, p. 2295 - 2298
作者:Sugimura, Takashi、Futagawa, Tohru、Tai, Akira
DOI:——
日期:——
Total synthesis of (.+-.)-africanol and (.+-.)-isoafricanol
作者:Weiming Fan、James B. White
DOI:10.1021/jo00065a018
日期:1993.6
A six-step synthesis of the sesquiterpenes africanol and isoafricanol from 3,5,5-trimethylcyclohex-2-en-1-one is reported. The anionic oxy-Cope rearrangement is used to prepare substituted 5-cyclodecenones functionalized with an allylstannane moiety, which, upon cyclization with the ketone, lead to hydroazulene derivatives. The stereochemistry in the transannular cyclization can be controlled through the choice of reaction conditions both with respect to the ring fusion itself and with respect to a preexisting chiral center. Cyclopropanation of the alkene that is generated following cyclization completes the synthesis of both compounds.
SUGIMURA, TAKASHI;FUTAGAWA, TOHRU;TAI, AKIRA, CHEM. LETT.,(1990) N2, C. 2295-2298