Tetrahedron

First direct synthesis of 3-hydroxy-pent-4-ynoic acids. Application to the synthesis of pyran-2-ones

ME Lopez-Reyes, JG López-Cortés, MC Ortega-Alfaro…

Index: Lopez-Reyes, Morelia E.; Lopez-Cortes, Jose G.; Ortega-Alfaro, M. Carmen; Toscano, R. Alfredo; Alvarez-Toledano, Cecilio Tetrahedron, 2013 , vol. 69, # 35 p. 7365 - 7372

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Citation Number: 7

Abstract

Abstract We describe a direct method for the synthesis of 3-hydroxy-pent-4-ynoic acids by the nucleophilic addition of bis-(TMS) ketene acetals to alkynones promoted by BF 3· Et 2 O. A systematic study involving electron withdrawing and electron donor groups (R 1= NO 2, CF 3, Br, Cl, H, Me, OMe) in the propargyl ketone reveals a strong dependence of electronic effects on the regiochemistry of the nucleophilic addition. Using a halolactonization ...