Thermal and photochemical reactions of sodium salts of .beta.-phosphono tosylhydrazones

Abstract

Thermal and photochemical reactions of sodium salts of P-phosphono tosylhydrazones have been investigated. When the sodium salt of dimethyl a-acetylmethylphosphonate tosylhydrazone is heated, the dimethoxyphosphonyl anior , though a relatively strong base, was eliminated. On the other hand, ultraviolet irradiation of the sodium salts of P-phosphono tosylhydrazones leads to dimethoxyphosphonyl-substituted olefins, presumably via the carbene intermediate. Some of the products result from a previously unreported phosphonyl group migration to a carbene.

Darzens Reaction of Acyl Phosphonates with α-Bromo Ketones: Selective Synthesis of cis- and trans-Epoxyphosphonates

“…To the best of our knowledge, a Darzens-type reaction including the use of acyl phosphonates has not been reported so far. Moreover, there are a vast number of methods for the synthesis of epoxyphosphonates, − in which there are no examples affording this type of highly functionalized epoxyphosphonates that could be useful intermediates in several reactions.…”

“…A straightforward method for the preparation of epoxyphosphonates is the direct epoxidation of the corresponding alkenyl phosphorus compound; however, several other methods also are available. − These methods include the reaction of α-halo ketones and α-tosyl ketones with metal dialkyl phosphites, − the cyclization of halohydrins in the presence of a base, , the Darzens-type reaction of chloromethyl phosphonates with carbonyl compounds, , and a rather recently published work, including a rhodium acetate-mediated reaction of diazobenzylphosphonates with carbonyl compounds . Although there are many methods for the preparation of these important intermediates, many of these methods lack stereoselectivity, efficiency, and ease of preparation of the starting materials, so there is still a need for alternative synthetic approaches.…”

The Schmidt Reaction of Dialkyl Acylphosphonates

“…The yields of each of these products were determined from the integration ratio in the NMR spectra of the mixed fractions (13c, 1%, and 14c, 1.5% yield). 14c was isolated by crystallization from methanol and had mp 132-133.5 °C: >H NMR 3.88 (d, 6H, 7PH = 11, CHf), 7.16 (m, 3H, arom), 7.61 (s, 1H, arom), 7.80 (br s, 1H, NZ/), 8.85 (s, 1H, NZ/); IR (KBr) v 3225, 3170, 2930, 2825, 1700, 1605, 1590, 1545, 1450, 1230, 1050; MS (m/e) 280, 278 (2, 7, M'+), 151 (14, [OCNPO(OMe)2]'+), 129, 127 (32, 100, [C1C6H4NH2]'+), 121 (80), 120 (24), 109 (8,2]+). Anal.…”

Phosphorylated aldehydes: Preparations and synthetic uses

“…Both symmetrical and unsymmetrical aliphatic and cyclic phosphorylated aldehydes 29 can be obtained by this way. [44][45][46][47][48] Fig. 13.…”