Synthesis of disparlure and monachalure enantiomers from 2,3-butanediacetals

Abstract

2,3-Butanediacetal derivatives were used for the stereoselective synthesis of unsymmetrically substituted cis-epoxides. The procedure was applied for the preparation of both enantiomers of disparlure and monachalure, the components of the sex pheromones of the gypsy moth (Lymantria dispar) and the nun moth (Lymantria monacha) using methyl (2S,3R,5R,6R)-3-ethylsulfanylcarbonyl-5,6-dimethoxy-5,6-dimethyl-1,4-dioxane-2-carboxylate as the starting material.

Recent advances in the synthesis of insect pheromones: an overview from 2013 to 2022

“…3 shows the structures of the fatty acid-derived epoxides synthesized during the selected time period. All epoxides were identied from the order Lepidoptera, namely, Lymantria monacha (Lep., Erebidae): 16; L. dispar (Lep., Erebidae): 17; [30][31][32][33] Ectropis obliqua (Lep., Geometridae): 18; [34][35][36][37] Itame argillacearia (Lep., Geometridae): 19; 38 Thyrinteina arnobia (Lep., Geometridae): 20; 39 Lymantria mathura (Lep., Erebidae): 21; 40 and Estigmene acrea (Lep., Erebidae): (9S,10R)-22. 41 The epoxy functional group was obtained by intramolecular nucleophilic displacement reactions (16,17), epoxidation of alkenes with reagents like mCPBA, 34,39 Ti(i-PrO) 4 37,40 (18, 20), or Sharpless asymmetric dihydroxylation (AD-mix), 37,38 followed by intramolecular epoxide ring-closing (18,19).…”

“…In a few cases, esters are derived from unbranched carboxylic acids and iso-branched short-chain alcohols (e.g. [30][31][32][33]64) and are included here. Fig.…”