Darstellung, Struktur und Reaktionsf�higkeit einiger Metallderivate des �thoxycarbonylmethan-phosphons�uredi�thylesters

Structural study of carbanionic species .alpha. to a phosphoryl group. The anion of diethyl [(carbomethoxy)methyl]phosphonate. Comparison with phosphorus-ylidic esters and acetoacetic esters anions

“…The comparison of the phosphono ester free anion with acetoacetate analogue 4 shows noticeable differences: the free anion 4 only adopts the (Z,£)-4b conformation,8 like 0 Discussion Comparison with Phosphorus Ylides and Acetoacetic Anions. Our results will be discussed in two respects: on one hand, the structure of the free anion 2, (28) (a) A. Regis and J. Corset, Chem.…”

“…[CH3COCHCOOC3H5]-M+ 3 4 Previous work on compound 2 deals with NMR spectra in pyridine and IR spectra in the solid state. 4 However, more comprehensive structural information can be gained from 13C and 31P NMR data, as well as from NMR and IR data in more or less associating conditions.…”

Routes to mitomycins. Application of iminium salts to the synthesis of naphthoquinone mitosene analogs

“…These difficulties led to a reexamination of the osmium tetraoxide catalyzed periodate cleavage of 26 which had proceeded erratically under standard conditions. We found that when the reaction was conducted at pH 6.5 instead of pH [4][5] as is normally the case, the yield was greatly improved. This change required the use of lithium periodate since sodium periodate is poorly soluble under these conditions.…”

Unexpected Reactivity of Ethyl 2-(Diethylphosphono)Propionate Toward 2,2-Disubstituted-1,3-cyclopentanediones

“…27,32,33 The additional lines in the spectrum may be rationalized by an assumption that phosphonate anions could give metal chelates not only through oxygen-atoms, but also involving carbon-atom and exist as dimers. 22,24,26 In 13 C-and 1 H-NMR spectra of anion 2a-A (Table III) at room temperature we followed the appearance of broad resonance signals, probably due to conformational exchange processes between isomers. In the 13 C-NMR spectrum of phosphonate 2a, the P-C(3) carbon (see atom were seen in two sets of doublets in 1:2 ratios, the latter is probably the sum of signals of two isomers (1:1 + 1).…”