Synthesis of new aliphatic and aromatic phytotoxic derivatives of 2alpha,4alpha-dimethyl-8-oxabicyclo[3.2.1]oct-6-en-3-one

Pest Manag Sci. 2003 Sep;59(9):1043-51. doi: 10.1002/ps.717.

Abstract

Several new compounds with potential herbicidal activity were synthesized from 2alpha,4alpha-dimethyl-6,7-exo-isopropylidenedioxy-8-oxabicyclo[3.2.1]octan-3-one (4). Seven aromatic alcohols were prepared by reaction of (4) with aryllithium reagents, where the aryl groups were 4-ethoxyphenyl (5, 70% yield), 4-ethylphenyl (6, 82% yield), 4-butylphenyl (7, 78% yield), 4-tert-butylphenyl (8, 81% yield), 2,4-dimethoxyphenyl (9, 75% yield), 2-ethylphenyl (10, 12% yield) and para-(4-bromophenoxy)phenyl (11, 24% yield). Reaction of the acetonide (4) with Grignard reagents formed also four aliphatic alcohols where the alkyl groups are ethyl (13, 78%), butyl (14, 85%), hexyl (15, 81%) and octyl (25, 92%). The alcohols (5), (6), (7), (8), (13), (14), (15) and (25) were reacted with thionyl chloride in pyridine, forming their respective alkenes (17, 76%), (18, 74%), (19, 83%), (20, 73%), (22, 78%), (26, 62%), (23, 77%) and (24, 66%). The effect of these compounds, at the concentration of 5.5 microg g(-1), on the development of radicle and aerial parts of Sorghum bicolor (L) Moench, Euphorbia heterophylla L, Brachiaria decumbens and Desmodium tortuosum DC was evaluated.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Brachiaria / drug effects
  • Bridged Bicyclo Compounds / chemical synthesis*
  • Bridged Bicyclo Compounds / toxicity
  • Chemical Phenomena
  • Chemistry, Physical
  • Euphorbia / drug effects
  • Fabaceae / drug effects
  • Herbicides / chemical synthesis*
  • Herbicides / toxicity
  • Hydrocarbons, Aromatic / chemical synthesis
  • Hydrocarbons, Aromatic / toxicity
  • Magnetic Resonance Spectroscopy
  • Magnoliopsida / drug effects*
  • Molecular Structure
  • Plant Roots / drug effects
  • Plant Shoots / drug effects
  • Poaceae / drug effects

Substances

  • 2alpha,4alpha-dimethyl-6,7-exo-isopropylidenedioxy-8-oxabicyclo(3.2.1)octan-3-one
  • Bridged Bicyclo Compounds
  • Herbicides
  • Hydrocarbons, Aromatic