Enantioselective Mukaiyama–Michael Reaction of Cyclic α-Alkylidene β-Keto Phosphine Oxide and Phosphonate and Asymmetric Synthesis of (<i>R</i>)-Homosarkomycin
β-oxo phosphates and phosphine oxides that proceeds in a highly enantioselective manner is described. It is possible to carry out these reactions using a catalytic amount of a bisoxazoline–Cu(II) complex without decreasing the enantioselectivity, and one of the products has been successfully used for the first enantioselectivesynthesis of (R)-homosarkomycin.
One pot synthesis of mono- and spirocyclic α-phosphonato-α,β-unsaturated cycloenones
作者:Jun Mo Gil、Jung Hwan Hah、Kwang Young Park、Dong Young Oh
DOI:10.1016/s0040-4039(98)00460-2
日期:1998.5
A one pot ozonolysis/intramolecular aldol condensation (with the aid of TsOH and Et3N as catalysts) of beta-keto-omega-alkenylphosphonates provided the alpha-phosphonato-alpha,beta-unsaturated cycloenone with good yields. (C) 1998 Elsevier Science Ltd. All rights reserved.
New Synthesis of 2-Oxo-3-alkenylphosphonates and Hetero Diels–Alder Reactions with Vinyl Ethers Leading to 5-Substituted 2-Phosphiny 1-2-cyclohexen-1-ones
作者:Eiji Wada、Shuji Kanemasa、Otohiko Tsuge
DOI:10.1246/bcsj.62.860
日期:1989.3
A new method of synthesizing phosphinyl-substituted enones, 2-oxo-3-alkenylphosphonates, is developed via the dianion of diethyl 2-oxopropylphosphonate. The enones serve as hetero dienes in thermal reactions with vinly ethers producing 2-alkoxy-6-(phosphinylmethyl)-3,4-dihydro-2H-pyrans. Acid-catalyzed cleavage of these cycloadducts is followed spontaneously by internal condensation furnishing 2-p
Diels–Alder chemistry of 2-diethoxyphosphinylcyclohex-2-enones. A new approach to complex phosphonates and synthetic applications of the β-keto phosphonate system
作者:Chiung-Fang Chien、Jen-Dar Wu、Tai Wei Ly、Kak-Shan Shia、Hsing-Jang Liu
DOI:10.1039/b109780f
日期:2002.1.30
Enone phosphonates 1 and 2 were found to be excellent dienophiles for the Diels-Alder reaction, giving phosphonate-containing polycycles, and the phosphonate group of the resulting adducts facilitated both the installation of an angular alkyl group via a reductive alkylation process and the regioselective generation of a ring junction double bond via an intramolecular Wadsworth-Horner-Emmons reaction