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cis-4a-Methyloctahydrophenanthrene (1) was prepared in 8 steps (23% overall yield) from 2-bromophenyl)acetic acid (3) and cyclohexane-1,3-dione (6). A highly cis-diastereoselective Michael-type Heck coupling served as the key step in the assembly of the tricyclic skeleton. This compound 1 was used as gas chromatography standard which allowed the unequivocal identification of a minor biomarker present in Carmopolis oil from the Sergipe-Alagoas Basin in Brazil.

A full account to the preparation and application of three appropriately substituted vinylcyclohexenes (2,2-dimethyl-3-vinylcyclohex-3-en-1-ol, 2,2-dimethyl-3-vinylcyclohex-3-en-1-one and 3,3-dimethyl-2-vinylcyclohexene) in thermal Diels-Alder reactions with alpha,beta-unsaturated esters (methyl tiglate and methyl angelate) is given. This approach delivered the racemic synthesis of ten octalin derivatives bearing a rearranged drimane skeleton (4 diastereomers of 1-methoxycarbonyl-6-hydroxy-1,2,5,5-tetramethyl-1,2,3,5,6,7, 8,8a-octahydronaphthalene; 1-methoxycarbonyl-6-oxo-1,2,5,5-tetramethyl-1,2,3,4,5,6,7,8-octahydronaphthalene; 2-methoxycarbonyl-6-oxo-1,2,5,5-tetramethyl-1,2,3,5,6,7,8,8a-octahydronaphthalene; 3 diastereomers of 1-methoxycarbonyl-1,2,5,5-tetramethyl-1,2,3,5,6,7,8,8a-octahydronaphthalene and 2-methoxycarbonyl-1,2,5,5-tetramethyl-1,2,3,5,6,7,8,8a-octahydronaphthalene) . Central synthetic features included preparation of enoltriflates by Stang's protocol and the successful palladium-catalyzed cross-coupling reaction (Stille reaction) of the triflate with the tri-n-butylvinylstannane. The octalins relative stereochemistry was unequivocally ascertained by spectroscopic methods and/or X-ray crystallography and these data now stand as useful tools to support the correct assignment of related natural products usually isolated in minute amounts.

The reactivity of terminal and trisubstituted double bonds of monoterpenes with HSCN has been examined by GC giving evidence that kinetics is responsible for the chemoselective addition to terminal double bonds in terpenes. The results show that the addition to the terminal double bond is about 17 times faster than for trisubstituted double bonds and that the presence of the first SCN group in the molecule prevents a second addition. The presence of a hydroxyl or methoxy group in the molecule, decreases the reaction kinetics. Based on these kinetic experiments a two steps synthesis of the natural product 7-isothiocyano-7,8-dihydro-alpha-bisabolene using bisabolol as starting material, was planned and successfully accomplished.

Most of the flower-pollinator interactions are based on rewards as pollen and nectar. Our group however, has been focusing on the chemical composition of unusual rewards like floral resins and floral oils. We are now reporting the chemistry of the floraloils of Oncidium pubes which are composed of diacylglycerols and triacylglycerols possessing one or two acetyl residues and one long chain fatty acid. The substitution pattern of some of the diacylglycerols was inferred to be 1, 3 based on spectroscopic analyses and comparison with 3 different synthetic compounds obtained from D-mannitol, oleic acid and acetic acid. The fatty acid residues possess double bond and/or acetoxy group as functional groups. Finally our results provided chemical evidences that pollination of Oncidium pubes is not based upon an attraction-deception system but on floral lipids and this is the first time this has ever been mentioned in the literature.

The use of diastereomeric alcohol dialkylphosphonate derivatives to determine the enantiomeric excesses via 31P-NMR signal ratios of anisochronous meso and threo isomers was successfully applied to secondary alcohols (Feringa?s method). Expansion of the methodology to primary alcohols possessing the hydroxyl groups thethered to the stereogenic centers by two or more methylene groups proved the method to be inefficent. The comparison between the coupled and decoupled spectra is important in order to identify the signals corresponding to the dialkylphosphonates. Nevertheless the methodology should be applied whenever the amount of the alcohol and its structure are not the limiting factors.

Product fragrance and performance are crucial for individuals choosing hair care products. Thus, fragrance raw materials should possess physicochemical characteristics that ensure good blooming upon product unpacking and during use and additionally exhibit good substantivity on hair fibers. To investigate the influence of fragrance raw material characteristics, hair damage level, and ethnicity on fragrance substantivity on hair fiber, hairs of different ethnicities were chemically and thermally damaged. Along with this, the level of damage was characterized by attenuated total reflectance Fourier-transform infrared spectroscopy, protein loss evaluation, scanning electron microscopy analysis, tensile test, and swelling test. The substantivity of each fragrance ingredient was evaluated for wet and dry hairs using gas chromatography coupled with mass spectroscopy. Our results indicated that the physicochemical properties of fragrance raw materials (mainly polarity) altered their availability within the shampoo formulation, as well as their substantivity on hair fibers. Furthermore, the substantivity of fragrance compounds was influenced by alterations in hair permeability and hydrophobicity caused by various damaging processes. [ABSTRACT FROM AUTHOR]

Photodynamic therapy has been used to treat a variety of diseases, however, there is continuing search for new biocompatible photosensitizers. Herein, we demonstrate for the first time that imidazo[1,2‐a]pyrimidine compounds are able to generate singlet oxygen species and can act as photosensitizers in the intracellular environment. Our results show that this class of compounds absorb and emit in the 400–500 nm region, present low cytotoxicity in the dark, are efficiently uptaken by cells, are fluorescent in intracellular medium, and generate singlet oxygen upon irradiation, killing cancer cells within 2 h at low concentration (2.0 μm). The imidazo[1,2‐a]pyrimidine compounds are a potential new tool for phototheranostics, because they can be simultaneously used for fluorescence imaging and photodynamic therapy. [ABSTRACT FROM AUTHOR]