Tetrahedron

Stereoelectronic stabilization in non-chair conformations of substituted-2, 3-dihydro-1, 4-benzod ioxepins

A Lachapelle, M St-Jacques

Index: Lachapelle, Alain; St-Jacques, Maurice Tetrahedron, 1988 , vol. 44, # 16 p. 5033 - 5044

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Citation Number: 14

Abstract

2, 3-Dihydro-1, 4-benzodioxepin (5) and its 3-substituted derivatives 6–9 have been studied by 13C and 1H dynamic NMR in two solvent systems of different polarity. The aromatic signals were found to be quite sensitive to the nature of the seven-membered cyclic geometries and were used as “conformational probes”. The results show that the chair (C) conformation is the only form detected at-120° C for the parent compound 5 and its 3- ...