Reactions with trimethyl phosphite

Neruda, B. et al., J. Organomet. Chem., 1976, 111, 241-248 In the exothermic reaction with trimethyl phosphite to give r/.v-dimethyl-bis(trimethyl phosphito)platinum, the azide must be added to the phosphite in small portions with stirring. Addition of the phosphite to the solid azide led to a violent explosion, probably involving the transitory by-product methyl azide. 

Figure 3. The percent of benzyl chlorines replaced in a reaction with trimethyl phosphite as a function of reaction time (measured by weight gain). The reaction time is measured from the time the reaction bath reached 100°C.

There is a dearth of reliable methods available for determining ethylenic groups as components of quinonoid ring systems in lignin. A sensitive and specific method developed by Lebo et al. (1990), based on an addition reaction with trimethyl phosphite, has been used to determine o-quinonoid structures in situ in the lignin component of refiner mechanical pulp. 31P-NMR measurement capability is required for the analysis. 

A method has been described for the functionalization of the isopropylidene terminus of isoprenoids. For example, geranyl benzyl ether (208) was converted into the phenyl thioether (210) by treatment with PhSCl and elimination of HCl. Oxidation and reaction with trimethyl phosphite gave the primary alcohol (209) stereospecifically in 75% overall yield. Use has been made of this procedure in the synthesis of solanesol (C45) from three C15 units.The tosyl derivative of the hydroxylated farnesol (211) reacts with the bromide (212) prepared from (213) to give the C30 product (215), the bromide (216) of which, after further reaction with (214), affords the solanesol derivative (217) and thence solanesol (205). 

The deoxygenation of nitrile oxides is rarely an important reaction, but some of the standard methods referred to above have been used, including reaction with trimethyl phosphite and with iron pentacar-... 

An efficient asymmetric synthesis of P-aminoalkylphosphonates 212 via addition of phosphonate carbanions to enantiopure sulfinimines has been reported (Scheme 25). A range of novel 3-phosphonocyclobutyl amino acids have been prepared via the versatile intermediate 3-oxocyclobutylphosphonate (213) (Scheme 26). Sphingosine-1-phosphonate (215) has been synthesised from the 2-A,3-0-protected 1-0-mesyl derivative 214 of sphingosine via conversion to the bromide and an Arbuzov reaction with trimethyl phosphite.Chain extension of 215 provided a route to homo-sphingosine-1-phosphonate (216). 

As might be expected, keto-sugar acetates undergo the Perkow reaction with trimethyl phosphite to give a mixture of enol phosphates (27) and (28). In other cases the products appear to be dependent on the leaving group, and the Perkow products... 

The dimethyl 2-methoxycarbonyl-2-(methoxyimino)ethylphosphonate used in the Homer-Wadsworth-Emmons reaction as an amino acid synthon is prepared by masking the carbonyl group of methyl bromopymvate with methoxyamine hydrochloride before submission to a Michaelis-Arbuzov reaction with trimethyl phosphite (Scheme 8.37).5 "5 By contrast, unprotected 3-benzoyl-... 

Mevinphos (96, Phosdrin ) is prepared from methyl 3-chloroacetoacetate in reaction with trimethyl phosphite. Mevinphos (Phosdrin ) is a mixture of Z and E stereoisomers in which the Z isomer was found to be 100 times more active.54 In contrast to mevinphos, E and Z isomers of bromfenvinphos (92) and chlorfenvinphos (94) show no significant difference for a number of biological properties for insecticides.55 The less toxic Clodrin (98) is synthesized from the 1-phenylethoxy ester of 3-chloracetoacetate 97 which is used for control of ectoparasites in horses, cattle, sheep, and swine.54... 

Amino-l-hydroxyethylene-l,l-bisphosphonic acid 2 has been synthesized from Af-phthaloylglycme [142]. Treatment of Af-phthaloylglycme with thionyl chloride gave the corresponding acid chloride, which on reaction with trimethyl phosphite, furnished a-ketophosphonate 1. Addition of dimethyl H-phosphonate to the carbonyl gronp of 1 gave 2. 

The synthesis of the target compounds started from tetra-O-benzyl derivative 101 (90HCA1338) (Scheme 25). Ozonolysis followed by the Abramov reaction with trimethyl phosphite in acetic acid gave a 3 2 ratio of the epimeric phosphonates 102 and 103. Conversion of 102 to the corresponding cyclic phosphonate with aqueous sodium hydroxide gave a mixture of the methyl esters 104 and 105 (1 2). From each isomer, reduction... 

Optically active 4-acyloxyazetidin-2-ones are readily available from penicillin sulphoxides by reaction with trimethyl phosphite and a carboxylic acid (Scheme 91). The thiazolidine ring of penicillin sulphoxides may also be cleaved to give... 

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