This paper focuses on the thermochemistry of some derivatives of cyclopenta1,3-diene, namely, 5-methylcyclopenta-1,3-diene, 5-ethylcyclopenta-1,3-diene, 5-formylcyclopenta-1,3-diene, 5-methylcyclopenta-1,3-diene-1-yl radical, 5-ethylcyclopenta-1,3-diene-1-yl radical, 5-carbonylcyclopenta-1,3-diene radical, 1-formylcyclopenta-2,4-diene-1-yl radical, 5methylenecyclopenta-1,3-diene radical, 5-ethy...

A reactivity difference based on the position of substituents on cyclohexa-1,3- diene was observed for the title reaction. The effect of water as solvent was more distinct for 1-methyl-4-isopropylcyclohexa-1,3-diene than for 2-methyl-5-isopropylcyclohexa- 1,3-diene or non-substituted cyclohexa-1,3-diene. The effect of NaCl (salting-out) and guanidium chloride (salting-in) was also large for 1-m...

The presence of a di-unsaturated highly branched isoprenoid (HBI) lipid biomarker (diene II) in Southern Ocean sediments has previously been proposed as a proxy measure of palaeo Antarctic sea ice. Here we show that a source of diene II is the sympagic diatom Berkeleya adeliensis Medlin. Furthermore, the propensity for B. adeliensis to flourish in platelet ice is reflected by an offshore downwa...

In the title compound, C(29)H(25)NS(2), both the Cl atoms of the aza-diene precursor 4,4-dichloro-1,1-diphenyl-2-aza-buta-1,3-diene are replaced by two vicinal S-p-tolyl substituents attached to the terminal C atom of a π-conjugated 2-aza-butadiene array. The aza-diene chain is planar to within 0.01 Å. One of the phenyl rings seems to be slightly π-conjugated with the aza-diene core [dihedral a...

We report the first synthesis of a cobalt Cp diene complex wherein the diene is derived by microbial dearomatising dihydroxylation of an aromatic ring. The complex has been characterised crystallographically and its structure is compared to that of an uncomplexed diene precursor.

Soybean and linseed oils were selectively hydrogenated with copper-on-silica gel catalyst. The linolenate content of the oils was reduced to diene and monoene with no appreciable increase in saturates. Hydrogenated soybean oils contained 68-76% monoene, 11-18% diene, 0% conjugated diene and triene, 1-6% conjugatable diene, 0-0.3% conjugatable triene, and 23-40% isolated trans double bonds. Hydr...

The biotransformation of lithocholic acid by Pseudomonas sp. strain NCIB 10590 under anaerobic conditions was studied. The major products were identified as androsta-1,4-diene-3,17-dione and 3-oxochol-4-ene-24-oic acid. The minor products included 17beta-hydroxyandrost-4-ene-3-one, 17beta-hydroxyandrosta-1,4-diene-3-one, 3-oxo-5beta-cholan-24-oic acid, 3-oxochola-1,4-diene-24-oic acid, 3-oxopre...

(1E,3E)-1,4-Diphenylbuta-1,3-diene is photostable in the crystalline state, while fluoro-substitution induces reactivity. Crystals of (1E,3E)-1-pentafluorophenyl-4-(4-methoxyphenyl)buta-1,3-diene 1, (1E,3E)-1-pentafluorophenyl-4-(4-methylphenyl)buta-1,3-diene 2 and (1E,3E)-l-pentafluorophenyl-4-phenylbuta-1,3-diene 3 undergo double [2+2] photodimerization topochemically to yield anti head-to-ta...

Intramolecular cyclization of (h-diene)Fe(CO)3 complexes bearing a carboxylic acid chloride functionality at the terminal side chain of the diene ligand produces (s, h-allyl)Fe(CO)3 complexes, whereas treatment of the acid chloride complexes with Et3N and AlCl3 provides (h-diene)Fe(CO)3 complexes containing a cyclopentanone moiety. © 2000 Elsevier Science S.A. All rights reserved.

Four new cucurbitane-type triterpenes, cucurbita-5,23(E)-diene-3beta,7beta,25-triol (1), 3beta-acetoxy-7beta-methoxycucurbita-5,23(E)-dien-25-ol (2), cucurbita-5(10),6,23(E)-triene-3beta,25-diol (5), and cucurbita-5,24-diene-3,7,23-trione (6), together with four known triterpenes, 3beta,25-dihydroxy-7beta-methoxycucurbita-5,23(E)-diene (3), 3beta-hydroxy-7beta,25-dimethoxycucurbita-5,23(E)-dien...