Synthesis of All the Stereoisomers of 7-Methylheptadecane and 7,11-Dimethylheptadecane, the Female Sex Pheromone Components of the Spring Hemlock Looper and the Pitch Pine Looper

Phenothiazine Derivatives: The Importance of Stereoisomerism in the Tolerance and Efficacy of Antimicrobials

“…A racemic mixture of JBC 1847 was synthesized from promazine at The Department of Chemistry, Faculty of Science, University of Copenhagen as previously described [ 7 ]. Subsequently, (S)-JBC 1847 was purified from this racemic mixture of JBC 1847 from (S)-Citronellol tosylate (Sigma aldrich, Roskilde, Denmark), prepared according to the protocol published by Shirai et al 1999 [ 11 ].…”

Chemometric Classification of Motor Oils Using 1 H NMR Spectroscopy With Simultaneous Phase and Baseline Optimization

“…Except for PAO-based oils, the samples are well arranged along the PC2 axis with the following trend: mineral The differentiation of HC oils along PC2 is achievable mainly due to positive loadings for two overlapping doublets at ~ 0.84 ppm. Based on the heterocorrelated spectra of HC base stocks, we attributed these signals to CH 3 branches in 6-methylalkyl and 6 + -methylalkyl (i.e., internal CH 3 -branched [46]) fragments resulting from isomerization. The increased levels of internal CH 3 -branched fragments in HC oils are also manifested by the appearance of an upfield shoulder on the main CH 2 signal due to the CH 2 units γ to the internal methyl branch (at ~1.23 ppm, not shown), thus confirming the above assignment.…”

Isolation and determination of absolute configurations of insect-produced methyl-branched hydrocarbons

“…The absolute configurations of the 36 isolated MBCHs were determined with a digital polarimeter with a smallvolume optical cell. Scattered reports in the literature indicated that monomethyl-branched alkanes with the (R)-configuration all exhibited negative optical rotations (36)(37)(38)(39)(40)(41)(42)(43)(44). These data were confirmed by measuring the specific rotations of ∼50 synthesized standards of both (R)-and (S)-configurations, with chain lengths from 25 to 35 carbons and methyl branches on carbons 3-13 (Table S1).…”