Hypervalent Iodine Oxidation of Flavanones: A New Synthesis of Methyl 2-Aryl-2,3-dihydrobenzofuran-3-carboxylates by 1,2-Aryl Shift
作者:Om Prakash、Madan P. Tanwar
DOI:10.1246/bcsj.68.1168
日期:1995.4
Flavanones (1), on oxidation with (diacetoxyiodo)benzene-sulfuric acid (DIB–H2SO4) or (hydroxy)tosyloxy)iodo)benzene (HTIB) in trimethyl orthoformate, undergo facile ring contraction by 1,2-aryl shift, thereby yielding methyl 2-aryl-2,3-dihydrobenzofuran-3-carboxylates (4) as major products (40—80%). cis-3-Methoxyflavanones (5) and flavones (3) are the minor products formed in variable ratios.
黄烷酮 (1) 在用原甲酸三甲酯中的(二乙酰氧基碘)苯-硫酸(DIB–H2SO4)或(羟基)甲苯磺酰氧基)碘)苯(HTIB)氧化时,通过 1,2-芳基位移发生容易的环收缩,从而产生2-芳基-2,3-二氢苯并呋喃-3-羧酸甲酯 (4) 作为主要产物 (40-80%)。顺式 3-甲氧基黄烷酮 (5) 和黄酮 (3) 是以可变比例形成的次要产物。