Molecular "Building Block" and "Side Chain Engineering": Approach to Synthesis of Multifunctional and Soluble Poly(pyrrole phenylene)s.

Here, the synthesis of a novel poly(pyrrole phenylene) (PpyP) that is both modular in ways of functionalization and soluble in organic solvents is reported, and therefore solution processable. This is achieved through the functionalization of the side-chain substituents in pyrrole phenylene (PyP) repeating units. Butyl acrylate brushes are first grafted through atom transfer radical polymerization from one type of PyP, followed by oxidative chemical co-polymerization of the grafted PyP with a PyP bearing different side chains-either an azide or a methoxy moiety, resulting in a soluble PpyP where solubility is not dopant-dependent.

Modular Synthesis and Biological Investigation of 5-Hydroxymethyl Dibenzyl Butyrolactones and Related Lignans.

Dibenzyl butyrolactone lignans are well known for their excellent biological properties, particularly for their notable anti-proliferative activities. Herein we report a novel, efficient, convergent synthesis of dibenzyl butyrolactone lignans utilizing the acyl-Claisen rearrangement to stereoselectively prepare a key intermediate. The reported synthetic route enables the modification of these lignans to give rise to 5-hydroxymethyl derivatives of these lignans.

Total Synthesis of (-)-Bicubebin A, B, (+)-Bicubebin C and Structural Reassignment of (-)-cis-Cubebin.

The first total synthesis of (-)-bicubebin A, and two previously unreported dilignans, (-)-bicubebin B and (+)-bicubebin C has been achieved through the dimerization of (-)-cubebin, confirming the structure and absolute stereochemistry of (-)-bicubebin A. Analysis of the data for (-)-bicubebin B showed it matched that of reported compound (-)-cis-cubebin. The NMR data of the subsequently synthesized proposed structure of cis-cubebin confirmed that its original proposed structure was incorrect.

Total Synthesis of Ovafolinins A and B: Unique Polycyclic Benzoxepin Lignans through a Cascade Cyclization.

Ovafolinins A and B, isolated from Lyonia ovalifolia var. elliptica, are lignans that contain a unique bridged structure containing a penta- and tetracyclic benzoxepin and an aryl tetralin. We report the first total synthesis of these natural products in which an acyl-Claisen rearrangement was initially utilized to construct the lignan backbone with correct relative stereochemistry.