Publication

Zum Ablauf der Wittig-Reaktion : zyklische oder ringoffene Zwischenstufen ?

Manfred Schlosser
1975
Journal Articles

Abstract

Low temp. 31P NMR indicated that the reaction of Ph3P+C-RR1 (I, R = R1 = H, Me) with R2COR3 (R2 = R3 = H; R2 = Ph, R3 = H) under salt free conditions gave the corresponding oxaphosphetane (II); in the presence of Li salts, esp. in Et2O, Ph3P+CRR1CR2R3OLi X- (III) were formed. II (R = Li, R1 = Me, R2 = H, R3 = Ph), formed from II (R = R2 = H, R1 = Me, R3 = Ph) and alkyllithium reagents, rearranged slowly at -78 Deg and rapidly at -20 Deg to give Ph3P+C-MeCH(OLi)Ph. The reaction of I with benzaldehydes had r 1.1 which indicated that the transition states were highly polar and that the ylide acted as a nucleophile. The intermediacy of III in the Wittig reaction and in the formation of the oxaphosphetane was discussed. [on SciFinder (R)]

Official source

https://infoscience.epfl.ch/entities/publication/210cdda6-1980-49af-929f-a6f841d9e4a2

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Manfred Schlosser
1975
Journal Articles

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/210cdda6-1980-49af-929f-a6f841d9e4a2

About this result

Related concepts (15)

In chemistry, pH (piːˈeɪtʃ ), also referred to as acidity, historically denotes "potential of hydrogen" (or "power of hydrogen"). It is a scale used to specify the acidity or basicity of an aqueous solution. Acidic solutions (solutions with higher concentrations of hydrogen () ions) are measured to have lower pH values than basic or alkaline solutions. The pH scale is logarithmic and inversely indicates the activity of hydrogen ions in the solution. where [H+] is the equilibrium molar concentration (mol/L) of H+ in the solution.

Organolithium reagent

In organometallic chemistry, organolithium reagents are chemical compounds that contain carbon–lithium (C–Li) bonds. These reagents are important in organic synthesis, and are frequently used to transfer the organic group or the lithium atom to the substrates in synthetic steps, through nucleophilic addition or simple deprotonation. Organolithium reagents are used in industry as an initiator for anionic polymerization, which leads to the production of various elastomers.

PH indicator

A pH indicator is a halochromic chemical compound added in small amounts to a solution so the pH (acidity or basicity) of the solution can be determined visually or spectroscopically by changes in absorption and/or emission properties. Hence, a pH indicator is a chemical detector for hydronium ions (H3O+) or hydrogen ions (H+) in the Arrhenius model. Normally, the indicator causes the color of the solution to change depending on the pH. Indicators can also show change in other physical properties; for example, olfactory indicators show change in their odor.

Related publications (1)

Zum Ablauf der Wittig-Reaktion : zyklische oder ringoffene Zwischenstufen ?

Chat with Graph Search

Electrochemical reductive stability of lithium hydridoborate solid-state electrolytes