Syntheses of γ-Oxo Acids or γ-Oxo Esters by Photooxygenation of Furanic Compounds and Reduction Under Ultrasound: Application to the Synthesis of 5-Aminolevulinic Acid Hydrochloride
作者:L. Cottier、G. Descotes、L. Eymard、K. Rapp
DOI:10.1055/s-1995-3897
日期:1995.3
The photooxygenation of 5-hydroxymethyl-2-furfural (1a) or derivatives 1b-g yields 4-hydroxy-Π2-butenolides 2 which are the precursors of butenolides 3 or α,β-unsaturated γ-oxo esters 5. The selective reduction of olides 2 or oxo esters 5 with zinc in acetic acid under sonication leads to γ-oxo acids 4 or γ-oxo esters 6. The photooxygenation of amino derivative 1d, followed by selective reduction of corresponding lactone 2d, gives 5-aminolevulinic acid hydrochloride (7) (ALA) after hydrolysis.
5-hydroxymethyl-2-furfural (1a) 或衍生物 1b-g 经过光氧合反应可生成 4-hydroxy-Î 2-butenolides 2,这是丁烯内酯 3 或 α,β-不饱和 γ-oxo esters 5 的前体。在乙酸中用锌在超声条件下选择性还原烯醇内酯 2 或氧代酯 5,可得到δ-氧代酸 4 或δ-氧代酯 6。氨基衍生物 1d 光氧合后,选择性还原相应的内酯 2d,水解后得到 5-氨基乙酰丙酸盐酸盐 (7)(ALA)。