intramolecular SN2′ cyclization reaction for the construction of critical C-ring in the nitrogen impregnated steroidal architectures bearing unsaturation at Δ9(11) position. In the endeavour to synthesize some new congeners, the remote electronic impact of the electron donating groups in A ring and heteroatoms like oxygen in B ring, on the propensity of C-ring cyclization was also observed.
已经描述了在温和的反应条件下使用
L-脯氨酸来访问14-氮杂类
固醇的有效手性池方法。关键步骤涉及分子内的S N 2'环化反应,以在含氮的甾族结构中在Δ9 (11)位置携带不饱和键,以构建关键的C环。为了合成一些新的同类物,还观察到了A环上给电子基团和B环上的氧等杂原子对C环环化倾向的远程电子影响。