Highly efficient macrolactonization of ω-hydroxy acids using benzotriazole esters: synthesis of Sansalvamide A.
A facile and mild macrolactonization reaction of ω-hydroxy acids was developed based on the transesterification of benzotriazole esters. Treatment of ω-hydroxy acids with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and 1-hydroxy benzotriazole (HOBT) in chloroform provided macrolactones in excellent yields. The reactions were performed under basic, neutral and acidic conditions using N,N-dimethylaminopyridine (DMAP), tetrabutylammonium tetrafluoroborate (TBABF(4)) and BF(3)·Et(2)O, respectively. A calcined hydrotalcite was also used instead of DMAP. Finally, to test the scope of the protocol in the synthesis of biologically relevant macrolactones, the total synthesis of Sansalvamide A was carried out.
Morales-Serna
José Antonio
JA
Instituto de Química, Universidad Nacional Autónoma de México Circuito Exterior, Ciudad Universitaria, Coyoacán 04510, México D.F., México.
Sánchez
Ericka
E
Velázquez
Ricardo
R
Bernal
Jorge
J
García-Ríos
Eréndira
E
Gaviño
Rubén
R
Negrón-Silva
Guillermo
G
Cárdenas
Jorge
J
D047630:Depsipeptides / Q000138:chemical synthesis* / Q000737:chemistry; D004952:Esters / Q000138:chemical synthesis / Q000737:chemistry; D006880:Hydroxy Acids / Q000138:chemical synthesis / Q000737:chemistry*; D014230:Triazoles / Q000138:chemical synthesis / Q000737:chemistry*
D047630:Depsipeptides; D004952:Esters; D006880:Hydroxy Acids; D014230:Triazoles; C119376:sansalvamide A; C012771:benzotriazole