A comparison of the (13)C nuclear magnetic resonance chemical shifts of some 15,16-dialkyl-15,16-dihydropyrenes with the corresponding 15,16-dialkyl-2,7,15,16-tetrahydropyrenes provides a measure of the effect of ring current on carbon-13 chemical shifts in which other effects may be expected to be negligibly small. The general conclusion is that the absolute magnitude of the ring-current effec...

Protonation of the highly reactive 1:l intermediate produced in the reaction between triphenylphosphine and dimethyl acetylenedicarboxylate by 2- hydroxyacetophenone leads to vinyltriphenylphosphonium salt, which undergoes aromatic electrophilic substitution reaction with the conjugate base to produce compounds 4,5, and 6 in 1 : 1.2:0.5 ratios

Iron(II) and iron(III) salts catalyze the oxidative alpha-phosphonation of N,N-dimethylanilines with dialkyl H-phosphonates in the presence of tert-butylhydroperoxide.

The substrate specificity of fumarase has been studied by measuring the ability of the enzyme to hydrate or dehydrate derivatives of fumarate and L-malate. Fumarase was observed to hydrate fumarate and its derivatives in the order, fluorofumarate > fumarate > chlorofumarate > bromofumarate > acetylenedicarboxylate > iodofumarate > mesaconate. With the exception of fluorofumarate, water was adde...

The Cosmetic Ingredient Review Expert Panel (Panel) reviewed the safety of 6 dialkyl malate compounds used in cosmetics. These ingredients function mostly as skin-conditioning agents-emollients. The Panel reviewed relevant animal and human data related to the ingredients along with a previous safety assessment of malic acid. The similar structure, properties, functions, and uses of these ingred...

An efficient and generally applicable protocol for palladium-catalyzed oxidative deacetonative coupling of 4-aryl-2-methyl-3-butyn-2-ols with dialkyl H-phosphonates has been developed. This methodology provides a new and practical route to alkynylphosphonates using the inexpensive 4-aryl-2-methyl-3-butyn-2-ols as the alkyne sources. This reaction could also be performed with aryl bromides, 2-me...

alpha-Keto amides 10a,b, formed from reaction of pyruvic or benzoylformic acid with allyl amine are found to present as single rotameric forms whilst their tertiary amido analogues 10c, d present as two rotamers in solution at rt. The hydroxyimino derivatives 8 share the conformational characteristics of their parents. The geometrical make-up of the new alpha-amidooximes is seen to depend on th...