Barriers to ring inversion in two alkoxy-1,3-dioxans

Abstract

It has been shown that the barriers for the more stable to less stable chair inversion in two alkoxy-1.3-dioxans are very close to those previously found for 1.3-dioxan and its 2-methyl derivative. This implies that the major contribution to the ring inversion barrier is associated with torsional strain and is unaffected by the type of substituent present in the ring.

Proton and carbon-13 nuclear magnetic resonance studies of the conformational dynamic properties of seven-membered rings. 2,4-Benzodioxepin and its derivatives

“…Table II. Carbon-13 Chemical Shift Data for Compounds [5][6][7][8][9][10] 33.87 (C-2') 24.51 (C-3') 27.06 (C-4') -101 139.47 127.91, 127.39 103.78 65.03" 34.26 (C-2')" 24.29 (C-3')" 26.32 " Solutions in CHF2CI containing internal Me4Si and CD2CI2 (13%) for field locking purpose. * The lines labeled c are more intense than the b lines (c = 79%; b = 21%).…”