152401-77-9Relevant academic research and scientific papers
Hetero-Diels-Alder reactions of α-carbonylated styrylphosphonates with enol ethers. High-pressure influence on reactivity and diastereoselectivity
Al-Badri, Hashim,Maddaluno, Jacques,Masson, Serge,Collignon, Noel
, p. 2255 - 2266 (2007/10/03)
Variously substituted α-carbonylated styrylphosphonates 5 were easily prepared by Knoevenagel-type syntheses, and used as oxadienes in hetero-Diels-Alder [4 + 2] cycloadditions with enol ethers, to give new phosphonylated 3,4-dihydro-2H-pyrans 6. It was confirmed that the reactivity, as well as the trans-diastereoselectivity of the reaction, was significantly enhanced by the use of high-pressure conditions, particularly in the presence of ButOH as a co-solvent. Moreover, a one-pot synthesis of 6 via a tandem-sequence Knoevenagel and hetero-Diels-Alder reactions was achieved.
Novel synthesis of α-acetylstyrylphosphonates
Sakoda,Matsumoto,Seto
, p. 705 - 713 (2007/10/02)
α-Acetylstyrylphosphonates were conveniently synthesized from 2-oxopropylphosphonates and substituted (dimorpholinomethyl)-benzenes (animals). 4-Benzylidenemorpholinium carboxylates, generated from animals by the action of α-halo acids, reacted with the phosphonates to give the products by elimination of the amine. The yields were influenced by the nature of substituents and their position in the phenyl ring and could be improved by adjustment of the acidities of the reacted acids. α-Acetylstyrylphosphonates containing various substituents on every position (at the 2-, 3-, or 4-position) in the phenyl ring were obtained generally in excellent yields using monochloroacetic acid.
