Synthesis of chiloglottones--semiochemicals from sexually deceptive orchids and their pollinators

Org Biomol Chem. 2009 Oct 21;7(20):4296-300. doi: 10.1039/b912233h. Epub 2009 Aug 17.

Abstract

A five-step synthesis of monoalkyl- and 2,5-dialkyl-1,3-cyclohexanediones (1) is described via a sequence involving sequential Birch reductions and alkylations from the readily accessible and inexpensive starting material, 3,5-dimethoxybenzoic acid. Two approaches were considered in which alkylation at C-2 occurs either prior or subsequent to the proposed reduction. The successful route, in which Birch reduction of a 3-alkyl resorcinol derivative (3) precedes alkylation was applied in the synthesis of chiloglottone 1 (1dc), in 58% overall yield. Chiloglottone 1 is a member of a new class of natural products, representing a known sex pheromone of the thynnine wasp Neozeleboria cryptoides and pollinator attractant in the Australian sexually deceptive orchid genus Chiloglottis. The synthetic homologues were assessed for their biological activity via electroantennographic detection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chromatography, Gas
  • Cyclohexanones / chemical synthesis*
  • Cyclohexanones / metabolism
  • Deception*
  • Female
  • Hymenoptera / chemistry*
  • Hymenoptera / physiology*
  • Male
  • Orchidaceae / chemistry*
  • Orchidaceae / physiology*
  • Pollination*
  • Sex Attractants / chemical synthesis
  • Sex Attractants / metabolism

Substances

  • 2-ethyl-5-propylcyclohexan-1,3-dione
  • Cyclohexanones
  • Sex Attractants