Synthesis 2016; 48(09): 1371-1380
DOI: 10.1055/s-0035-1560422
paper
© Georg Thieme Verlag Stuttgart · New York

One-Pot Synthesis of Spirotetrahydrooxino[3,4-c]pyridines and Spirotetrahydrofuro[3,2-b]pyridin-2-ones via Lactonization from Activated Pyridyldihydroozaxoles and Bis(trimethylsilyl)ketene Acetals

Omar Gómez-García*
a   Instituto de Química-UNAM, Circuito Exterior, Ciudad Universitaria, Coyoacán, C.P. 04510, México D.F., México   Email: cecilio@unam.mx   Email: jogomez@encb.ipn.mx
,
Elizabeth Gómez
a   Instituto de Química-UNAM, Circuito Exterior, Ciudad Universitaria, Coyoacán, C.P. 04510, México D.F., México   Email: cecilio@unam.mx   Email: jogomez@encb.ipn.mx
,
Rubén A. Toscano
a   Instituto de Química-UNAM, Circuito Exterior, Ciudad Universitaria, Coyoacán, C.P. 04510, México D.F., México   Email: cecilio@unam.mx   Email: jogomez@encb.ipn.mx
,
Héctor Salgado-Zamora
b   Departamento Química Orgánica, Escuela Nacional de Ciencias Biológicas-IPN, Prolongación de Carpio y Plan de Ayala S/N, Colonia Santo Tomás, 11340 México, D.F., México
,
Cecilio Álvarez-Toledano*
a   Instituto de Química-UNAM, Circuito Exterior, Ciudad Universitaria, Coyoacán, C.P. 04510, México D.F., México   Email: cecilio@unam.mx   Email: jogomez@encb.ipn.mx
› Author Affiliations
Further Information

Publication History

Received: 30 November 2015

Accepted after revision: 05 February 2016

Publication Date:
01 March 2016 (online)


Abstract

5-Methyl-2-(pyridin-3-yl)-4,5-dihydrooxazole and 5-methyl-2-(pyridin-4-yl)-4,5-dihydrooxazole activated by triflic anhydride underwent lactonization with bis(trimethylsilyl)ketene acetals to provide tetrahydrooxino[3,4-c]pyridines and tetrahydrofuro[3,2-b]pyridin-2-ones. Formation of the product was controlled by the position of the pyridyl substituent at C-3 and C-4 of the pyridyldihydrooxazole. On the other hand, 1-(trifluoromethylsulfonamido)propan-2-yl picolinate was obtained under the same conditions from 5-methyl-2-(pyridin-2-yl)-4,5-dihydrooxazole.

Supporting Information