The fate of the tryptophan stereocenter in the synthesis of 7,10,16,16a-tetrahydro-11H-quinazolino[2′,3′:3,4]pyrazino[1,2-b]β-carboline-5,8-diones
摘要:
Condensation reactions of anthranilic acid with iminoethers 14-17 derived from tetracycles 9-13 to give the title hexacyclic compounds reflect a preferred trans-relationship for H(10)-H(16a) protons in C(7)-unsubstituted products and a cis-relatioship for H(7)-H(16a) protons in C(10)-unsubstituted analogs. This synthetic strategy is limited by the steric hindrance of the substituent at C(10). Theoretical calculations are in agreement with the experimental results. The regioselectivity in favor of the linear tetracyclic compound 11 with respect to 12 has also been confirmed. (C) 2000 Published by Elsevier Science Ltd.
The fate of the tryptophan stereocenter in the synthesis of 7,10,16,16a-tetrahydro-11H-quinazolino[2′,3′:3,4]pyrazino[1,2-b]β-carboline-5,8-diones
摘要:
Condensation reactions of anthranilic acid with iminoethers 14-17 derived from tetracycles 9-13 to give the title hexacyclic compounds reflect a preferred trans-relationship for H(10)-H(16a) protons in C(7)-unsubstituted products and a cis-relatioship for H(7)-H(16a) protons in C(10)-unsubstituted analogs. This synthetic strategy is limited by the steric hindrance of the substituent at C(10). Theoretical calculations are in agreement with the experimental results. The regioselectivity in favor of the linear tetracyclic compound 11 with respect to 12 has also been confirmed. (C) 2000 Published by Elsevier Science Ltd.