β-Aminophosphonic compounds derived from methyl 1-dimethoxyphosphoryl-2-succinimidocyclohex-3-ene-1-carboxylates

A Novel Strategy Towards Aminophosphonic Derivatives Based on the Diels-Alder Cycloaddition: Experimental and Theoretical Approaches

“…Removal of the chiral auxiliary [82][83][84], phosphonate hydrolysis, and other functionalization / cleavage of the cyclohexene moiety [48] should provide novel enantiomerically pure aminophosphonic derivatives. On the basis of ab initio calculations, we postulated that the replacement of the carbonyl oxygen by a sulphur atom should enhance the selectivity of the cycloaddition process.…”

“…The possibility of transforming the D-A adducts into various aminophosphonic derivatives has been fully exemplified with compounds 3 and 4 (see Scheme 5; X = C H 2 , Y = CO, R = Me and EWG = CO 2 Me) [48]. Hydrolysis of the succinimyl and phosphonate groups occurred in refluxing aqueous HCl; the relative configurations of the substituents of the cyclohexene rings were not modified.…”

Phosphorus-containing amino acids with a P–C bond in the side chain or a P–O, P–S or P–N bond: from synthesis to applications

“…In this context, this strategy was exploited for the reaction of aminodienes with phosphonate dienophiles to afford b-aminophosphonic acids. 127 The cycloaddition of the succinimide diene 396 to the activated vinyl phosphonate dienophile 397 bearing an electron-withdrawing ester led to the cycloadducts 398a-b with 93% yield as a mixture of endo/exo stereoisomers at a ratio of 65 : 35. Then, hydrolysis of the succinimide and the phosphonate gave the corresponding ammonium salts 399ab with 84% yield (Scheme 90).…”

Cleavage of alkenes by anodic oxidation

“…After treating the crude product with 20% hydrogen peroxide (3 ml) and conc. formic acid (6 ml) [4], followed by extraction with dichloromethane (3 Â20 ml) and an otherwise usual work-up led to nonanal (2, 0.04 g, 0.3 mmol, 6%) and nonanoic acid (3a, 0.62 g, 3.9 mmol, 78%).…”

“…It leads to carboxylic acids and aldehydes or ketones, which provide starting materials for a large variety of functional group interconversions and C,C-bond forming reactions. In the laboratory the method of choice is ozonolysis [1][2][3][4][5], in a few cases it is also applied on a technical scale [6][7][8], which, however, requires costly safety precautions. Other methods are the conversion to 1,2-diols followed by a glycol cleavage [9][10][11][12][13].…”