Abstract
A preparative separation of the cis- and transtrimethyl 3-phosphonoacrylates was accomplished by High Speed Liquid Chromatography (HSLC), The trans-trimethyl 3-phosphonoacrylate was treated with cyclopentadiene to yield a 3:1 mixture of dimethyl 3-endo-carbomethoxy-5- norborneny1-2-exo-phosphonate and dimethyl 3-exo-carbomethoxy-5-norbornenyl-2-endo-phosphonate. The cis-trimethyl 3-phosphonoacrylate was treated with cyclopentadiene to yield a 1:1 mixture of dimethyl 3-endo-carbomethoxy-5- norborneny1-2-endo-phosphonate and dimethyl 3-exo-carbomethoxy-5-norborneny1-2-exo-phosphonate. The addition of aluminum chloride in the reaction of transitriethyl 3-phosphonoacrylate with cyclopentadiene gave the same product ratio of 3:1 as the same reaction without aluminum chloride. The Diels-Alder reaction of trimethyl 3-phosphonoacrylate with isoprene gave a 3:1 mixture of dimethyl 4-methyl-6-carbomethoxy-3-cyclohexenylphosphonate and dimethyl 3-methyl-6-carbomethoxy-3-cyclohexenylphosphonate. The reaction of triethyl 3-phosphonoacrylate with butadiene yielded diethyl 6-carboethoxy-3-cyclohexenyl-phosphonate, which was brominated and dehydrohalogenated to afford diethyl 2-carboethoxyphenylphosphonate. The Diels-Alder reactions with isoprene and butadiene required either freshly distilled dienophile or the use of titanium tetrachloride as a desiccant for the reactions to proceed. Attempts to react furan with trimethyl 3-phosphonoacrylate were unsuccessful.
Hubbard, Robert Lane (1976). The Diels-Alder reactions of trialkyl 3-phosphonoacrylates. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -474137.