STUDIES RELATED TO THE SYNTHESIS OF (+/-)-PEDERIN .1. SYNTHESIS OF ETHYL PEDERATE AND BENZOYLSELENOPEDERIC ACID

The first in a series of 2 papers on the synthesis of the insect toxin pederin (1) begins with a discussion of syntheses of the ring A fragments (±)-ethyl pederate (2) and (±)-benzoylselenopederic acid (4). A silicon-mediated intramolecular cyclisation of a chloroformate onto an allyl silane (11) was used to introduce the ring A methylene group at C-4 in ethyl pederate. Conjugate addition of phenylselenomethyl-lithium to the α,β-unsaturated lactone (19) was a key step in the construction of (4). © 1990.