Date of Award
Spring 1988
Document Type
Thesis - Restricted
Degree Name
Master of Science (MS)
Department
Chemistry
First Advisor
Cremer, Sheldon E.
Second Advisor
Haworth, Daniel T.
Third Advisor
Donaldson, William A.
Abstract
Various phosphonium bromides, some of which contained a carboxylic acid functional group, were synthesized from trialkylphosphines and alkylbromides or 11-bromoundecanoic acid. 11-(Diphenylphosphine)undecanoic acid was synthesized from diphenylphosphine and 10-undecenoic acid using AIBN as a free radical initiator. Diphenyl-bis( 11-carboxyundecyl )phosphonium bromide was successfully prepared from the reaction of 11-(diphenylphosphine)undecanoic acid with 11-bromoundecanoic acid. The reported reaction of various aldehyde and ketone tosylhydrazones with dimethyl phosphite was repeated in our lab with no success. Consequently, a modified procedure was developed and used to obtain intermediates of the type (CH30)2(0)PCR1R2NHNHTos in good yields. The reaction time, which appeared to contain an induction period, for the different tosylhydrazones with dimethylphosphite ranged from 3 to 30 days and varied in each experiment. Although several experiments were run, the conditions which speed up the reaction have not been identified . Thermal decomposition or reversibility of such intermediates was observed when recrystallization was attempted. Knowing the properties of these intermediates, their reduction with sodium borohydride gave the desired dimethyl alkylphosphonates in good yields. Unfortunately the dimethyl acetophenylphosphonate could not be obtained. In an attempt to study the stereoselectivity of the dimethylphosphite addition .to tosylhydrazones, camphor and norcamphor tosylhydrazones were used. U nfortunately no addition products were obtained. Consequently a different approach was undertaken. Dimethyl and diethyl benzylaminophosphonates were prepared from benzalaniline and dimethyl or diethylphosphite. It was observed that the dimethylphosphite reacted faster than the diethylphosphite, and gave an improved yield. To probe the stereoselectivity of this reaction, camphor and norcamphor anil were used. Unfortunately, camphor anil did not react with the dimethyl phosphite. In contrast, norcamphor anil did react with dimethyl or diethyl phosphite to give the desired norcamphor aminophosphonates. It was shown by 1 H, 13C, and 31 NMR that these reactions selectively gave one isomer. Correlation of our 13C NMR data for dimethyl and diethyl norcamphor aminophosphonates with that reported for different exo and endo 2-norbornyl phosphorus compounds led us to conclude that the exo-norcamphor aminophosphonates were obtained. Asymmetric synthesis using the dimethyl norcamphor aminophosphonate and methyl lithium was attempted to give the corresponding chiral phosphorus product; however, no reaction was obtained.
Recommended Citation
Pacheco-Panhans, Katia, "Synthesis and Stereochemistry of Some Dimethyl and Diethyl Alkylphosphonates" (1988). Master's Theses (1922-2009) Access restricted to Marquette Campus. 2864.
https://epublications.marquette.edu/theses/2864