bonds stabilize the beta-turn conformation with a geometry that is very close to the ideal type II beta-turns. The synthesis of the spiro beta-lactams is achieved by Staudinger reaction of a cyclic ketene derived from N-bencyloxycarbonyl-L-proline acid chloride with an imine. This reaction allows the formation of the spiranic backbone in a single-step with high diastereoselectivity and good yields. The
                                    使用新型螺旋β-内酰胺的高级从头算方法(MP2 / 6-31 + G)进行的分子建模计算预测,这些系统可以在溶液中采用β-转二级结构。强大的分子内氢键使β-转角构象稳定,非常接近理想的II型β-转角。螺环β-内酰胺的合成通过衍生自N-苯并氧羰基-
L-脯氨酸酰
氯的环状烯酮与
亚胺的斯陶丁格反应来实现。该反应允许单步形成
芳烃骨架,具有高非对映选择性和高收率。获得的新螺-β-内
酰胺类化合物是使用公认的肽
化学方法制备不同类型拟肽的核心。