Irradiation of 4,4-dimethyl-3-[(2-cyclopentenyl)methoxy]-2-cyclohexen-1-one, prepared from 4,4-dimethyl-3-phenylthio-2-cyclohexen-1-one and (2-cyclopentenyl) methanol, gave a tetracyclic intramolecular [2+2]photocycloadduct 7. Treatment of 7 with iodotrimethylsilane followed with tributyltin hydride afforded 3,3,11-trimethylbicyclo[6.3.0]undecane-2,6-dione(12). Methylenation of 12 afforded 6-methylene-3,3,11-trimethylbicyclo[6.3.0] undecan-2-one, the known intermediate to precapnelladiene.
Total synthesis of the marine natural product (±)-precapnelladiene
作者:Goverdhan Mehta、A. Narayana Murty
DOI:10.1039/c39840001058
日期:——
A stereo-controlled total synthesis of the novel sesquiterpene precapnelladiene (1), isolated from the soft coral Capnella imbricata, is reported; the synthesis unequivocally establishes the stereochemistry of the natural product as (1).
A general stereocontrolled approach to the 5-8 fused ring system. Application to the total synthesis of the marine natural product (.+-.)-precapnelladiene