Now showing items 11-20 of 53
Synthesis of 2-hydroxy-3-substituted naphthoquinones using the Heck reaction
An efficient Heck coupling of 2-hydroxy-3-iodo-naphthoquinone with a series of electron-deficient alkenes in aqueous solution has been accomplished. The method is characterized by simple conditions and facile work-up to ...
Sudoku Puzzles for First-Year Organic Chemistry Students
We use sudoku puzzles to help the students (i) learn the correspondence between the names of the amino acids, their abbreviations, and codes and (ii) learn the correspondence between the names of the functional groups, ...
Estrogenic and serotonergic butenolides from the leaves of Piper hispidum Swingle (Piperaceae)
(Journal of Ethnopharmacology 129(2): 220–226, 2010)
Ethnopharmacological relevance: Our previous work has demonstrated that several plants in the Piperaceae family are commonly used by the Q’eqchi Maya of Livingston, Guatemala to treat amenorrhea, dysmenorrhea, and pain. ...
Aggregation Pheromone of Coconut Rhinoceros Beetle, Oryctes rhinoceros (L.) (Coleoptera: Scarabaeidae)
Male coconut rhinoceros beetles,Oryctes rhinoceros (L.), produce three sex-specific compounds, ethyl 4-methyloctanoate, ethyl 4-methylheptanoate, and 4-methyloctanoic acid, the first of which is an aggregation pheromone. ...
Aggregation pheromone of palmetto weevil, Rhynchophorus cruentatus (F.) (Coleoptera: Curculionidae)
5-Methyl-4-octanol is the major aggregation pheromone of the palmetto weevil,Rhynchophorus cruentatus (F.). The pheromone (cruentol) was identified by coupled gas chromatographic-electroantennographic (GC-EAD) analysis of ...
Efficient syntheses of streptocarpone and (±)-a-dunnione
An efficient divergent synthesis of both streptocarpone and racemic α-dunnione from lawsone are described. A one-pot, formal [3+2] cyclization to form a furanonaphthoquinone directly provided a common intermediate.
Transformation of presumptive precursors to frontalin and exo-brevicomin by bark beetles and the West Indian sugarcane weevil (Coleoptera)
(Z)-6-Nonen-2-one (1) has recently been shown to be the biosynthetic precursor for the aggregation pheromone exo-brevicomin (2) in mountain pine beetle (MPB) males, Dendroctonus ponderosae (Hopkins). We tested the hypotheses ...
Aggregation Pheromone of Palm Weevil, Dynamis borassi
4-Methyl-5-nonanol (1) is the male-produced aggregation pheromone of the palm weevil, Dynamis borassi (F.) from Colombia. The pheromone was identified by coupled gas chromatographic–electroantennographic detection (GC-EAD) ...
Synthesis of Iodinated Naphthoquinones Using Morpholine-Iodine Complex
(Synthetic Communications Vol. 34, No. 18, pp. 3389–3397, 2004, 2004)
The efficient synthesis of 2‐hydroxy‐3‐iodo‐1,4‐naphthoquinone (3), 2‐amino‐3‐iodo‐1,4‐naphthoquinone (4), and 2‐iodo‐1,4‐naphthoquinone (5) have been developed using the parent naphthoquinone in combination with the ...
Organic Acids without a Carboxylic Acid Functional Group
(Journal of Chemical Education 77(7):910-915. July 2000, 2000-07)
This paper presents several organic molecules that have been labeled as acids but do not contain a carboxylic acid functional group. The rationale for the nomenclature and appropriate explanations for the apparent acidity ...