A variety of chiral bis-pyrroles have been made readily accessible via acid-catalyzed condensation of chiral ketones with pyrrole. Three representative chiral ketones 2-4 taken from the chiral pool were transformed into the corresponding bis-pyrrole derivatives in a straightforward acid-catalyzed condensation. Chiral β-hydroxy ketone derivatives, prepared through proline-catalyzed aldol condensation of acetone and an aldehyde, are readily transformed into the corresponding dipyrrolylmethane by the acid-catalyzed condensation carried out in the same conditions. The crystal structure of the chiral dipyrrolylmethane 2 derived from the (-)-menthone was determined.
一系列手性双吡咯已通过手性酮与吡咯的酸催化缩合反应方便地制备。从手性池中选取的三种代表性手性酮2-4经过简单的酸催化缩合反应转化为相应的双吡咯衍生物。通过脯氨酸催化的丙酮和醛的醛缩反应制备的手性β-羟基酮衍生物,可以方便地在相同条件下通过酸催化缩合反应转化为相应的二吡咯甲烷。从(-)-薄荷醇衍生的手性二吡咯甲烷2的晶体结构已确定。