Transannular cyclization reactions of cyclooctane-1,5-dione and 5-ethoxycarbonylmethylenecyclooctanone upon treatment with diamines. An efficient one-pot synthesis of substituted 2,6-diazatricyclo[5.3.3.01,6]- and 2,5-diazatricyclo[4.3.3.01,5]-alkanes and a study of their acetylation products