Effect of Dielectric Constant of Medium on Conductance for Trimethylsulfonium Halides in Normal and Branched Alcohols

The conductance parameters, Λo (equivalent conductance at infinite dilution) and KA (association constant) for trimethylsulfonium halides (Bromide and Iodide) in methanol, ethanol, n-propanol, 2-propanol and n-butanol have been evaluated at 25°C from the conductance measurements. The values of Λo for different salts decrease with decreasing dielectric constant of medium (D) with some variations and are in the order of MeOH > EtOH > n-PrOH > 2-PrOH > n-BuOH. The association constants of the same salts in different alcohols increase with decreasing dielectric constant of medium and are in the order of n-BuOH > 2-PrOH > n-PrOH > EtOH > MeOH.

Synthesis of diastereomeric pheromones: adjacent methyl-branched alcohols and ketones

Racemic synthesis of adjacent methyl-branched alcohol and ketone pheromones is particularly considered for large scale trap of insects due to their similar activity to the chiral components in field trial. In this work, we presented a straightforward and effective strategy for racemic synthesis of adjacent methyl-branched alcohols to obtain the different diastereomer rates (threo: erythreo = 2:1 and 1:1) via Felkin-Anh model. No effect of alkyl chain lenth on stereoselectivity of adduct has been demonstrated. Moreover, the α-methyl ketones were effectively produced by microwave-assisted oxidation of the respective secondary alcohols using 2-iodoxybenzoic acid (IBX)