CHAPTER 2 AROMATICITY 81
as 3,8-methanoaza[10]annulene,260 and their alkoxy derivatives.261 Calculations for aza[10]annulene concluded that the best olefinic twist isomer is 2.1 kcal mol1 (8.8 kJ mol1) more stable than the aromatic form,262 and is probably the more stable form.