3,7-Diazabicyclo[3.3.0]octane-2,6-diones: synthesis, NMR spectra and structures

3,7-Diazabicyclo[3.3.1]nonane-2,6-diones: building of homo- and heterochiral crystals

“…11 The bond lengths and bond angles in the crystal structures of 2 and 4 are very similar to those in the previously investigated derivatives A and B of dilactams of the bicyclo[3.3.0]octane series. 2 The angles between five-membered rings in the structures of 2 and 4 are 72.3° and 71.8°, respectively, and are significantly smaller in comparison with the corresponding values in the A and B structures (110.3°). 2 -3 , m(MoKα) = 1.10 cm -1 , F(000) = 328.…”

“…Dilactam 1 was synthesised on the basis of tetraethyl propane-1,1,3,3-tetracarboxylate 6 using the method proposed by Knowles and co-authors 4 with the new aminomethylating reagent 1,3,5tris(4-methoxybenzyl)hexahydro-1,3,5-triazine. 2 N-Deprotection of 1 with cerium ammonium nitrate (CAN) 2 gives dilactam diester, and its subsequent deesterification leads to dilactam diacid 3. The latter was thermally decarboxylated to form parent dilactam 4.…”

3,7-Dimethyl-3,7-diazabicyclo[3.3.1]nonane-2,6-dione-1,5-dicarboxylic acid derivatives: synthesis, structure and resolution

“…As we have found recently, 1 the crystalline parent dilactam 3,7-diazabicyclo[3.3.1]nonane-2,6-dione forms expected 2 homochiral H-bonded helical suprastructures, whereas its 1,5-diethoxycarbonyl derivative 1 and the other parent dilactam 3,7-diazabicyclo[3.3.0]octane-2,6-dione 3 are self-assembled in heterochiral H-bonded tapes of the diagonal zigzag type. Each link of this zigzag is cloned in infinite columns, which are alternated in the direction of the skeleton packing (Scheme 1).…”

“…( 3 J HCNH 4.9 Hz), 2.96 (s, 6H, 3,7-NMe), 3.50 (dt, 2H, 4,8-H b , 2 J -12.2 Hz, 4 J H-9-CH2 vis 1.2 Hz), 3.76 (d, 2H, 4,8-H a , 2 J -12.2 Hz), 8.31 (sh. s, 2H, HN).…”

Chirality-directed co-crystallization of different configurationally opposite dialkyl 2,5-diazabicyclo[2.2.2]octane-3,6-dione-1,4-dicarboxylates

“…The second aspect is intensely developed crystal engineering by co-crystallization. 1,13,[17][18][19][20][21][22][23] Chirality-directed co-crystallization of different bislactams 5,6 and bisureas 24 is examined from this standpoint.…”