Physical Sciences and Mathematics Commons^™

Buttressing Effect In 3, 3' -Disubstituted-2, 2' -Three-Carbon-Atom Bridged Biphenyls, Yunn Hui Chiang

Masters Theses

Introduction

The configuration of biphenyl has been the subject of much investigation and many recent reviews (1, 5, 6, 7, 8, 17, 21, 22). Of particular interest has been the configuration of 2,2' -bridged biphenyl derivatives. The preparation of an optically active 2,2' -three-carbon-atom-bridged biphenyl having an ultraviolet absorption maximum at 250 mμ, has been recently described (14). Although the compound was easily racemized, this property requires that a non-planar configuration be assigned to this biphenyl (I). Furthermore, this ultraviolet spectra indicates that inter-ring conjugation must exist in the non-planar configuration.

The Reaction Of N, N-Disubstituted Ketohydrazones With Lead Tetraacetate, Elisabeth Cerda

Masters Theses

Introduction

The reaction of lead tetraacetate with compounds of the following general structure (not able to enter here) was first reported by Iffland and Criner (12). In the case of ketoximes (A = oxygern), a nitrosoacetate was produced which was oxidized to the more stable acetoxy-nitrocompound as follows: (not able to enter here)

The generality of the reaction was established by preparation of a series of acetoxy-nitrocompounds from alicyclic and aliphatic ketoximes. The apparently similar reaction of cyclohexanonephenylhydrazone (A = N-¢) with lead tetraacetate was reported, but the reaction product was not identified.