Structure of 1,4-diethyl-3,5-dimethoxy-1,4-dihydrobenzoic acid

<h2>Acta Crystallographica Section C</h2><h3>Crystal Structure Communications</h3><h3>0108-2701</h3> <h2>regular structural papers (organic compounds)</h2> Volume 49 Part 7 Pages 1404-1406 July 1993 <h2>Structure of 1,4-diethyl-3,5-dimethoxy-1,4-dihydrobenzoic acid</h2> M. Soriano-García, R. V. Iribe, A. L. Silva and L. A. Maldonado Acta Cryst. (1993). C49, 1404-1406 Structure of 1,4-Diethyl-3,5-dimethoxy-l,4- dihydrobenzoic Acidt M. SORIANO-GARCiA* AND R. VILLENA IRIBE lnstituto de Qu[mica, Universidad Nacional Aut6noma de Mdxico, Circuito Exterior, Ciudad Universitaria, Coyoacdn 04510, Mdxico DF On the other hand, metallation of 1-ethyl-3,5- dimethoxy-l,4-dihydrobenzoic acid with "BuLi in tetrahydrofuran, followed by ethylation (EtBr) is a completely diastereoselective alkylation process, affording as the only product a single isomer identi- fied by this structure determination as (1), the major isomer of the above reaction. The methoxy groups at C(3) and C(5) are nearly coplanar with the six-membered ring [dihedral angles of -2.7 (3) and 2.7 (3)°, respectively], while the ethyl groups at C(1) and C(4) are cis to each other and perpendicular to the six-membered ring A. L. SILVA AND L. A. MALDONADO Divisi6n de Estudios de Posgrado, Facultad de Qufmica, Universidad Nacional Aut6noma de Mdxico, Ciudad Universitaria, Coyoacdn 04510, Mdxico DF (Received 11 September 1992; accepted 7 January 1993) Abstract This X-ray diffraction study establishes the molecu- lar structure of the major isomer resulting from the Birch reduction and dialkylation (with EtBr) of 3,5- dimethoxybenzoic acid, according to the procedure t Contribution No. 1176 of the Instituto de Quimica, UNAM. © 1993 International Union of Crystallography Printed in Great Britain - all rights reserved 01 c7 o2 &"l 0 C3~03...