Aziridine-Metathesis based Approaches to Alkaloid Synthesis

The aim of the project is to synthesise (-)-morphine utilising aziridine and metathesischemistry. The thesis is divided into three chapters.Chapter 1 provides brief reviews on the subjects of total synthesis of morphine; ringrearrangementmetathesis (RRM) and regioselective ring-opening of aziridines.Chapter 2 focuses on the research findings in the past three years. Two routes, A and B,were investigated in attempts to synthesise morphine (Scheme 1). In route A, sulfonylcyclopentene II was prepared from ring-closing metathesis of a diene precursor, whichwas synthesised from lithiated cinnamylsulfone and butadiene monoxide. Subsequently,RRM reactions of several [alpha]-SO2Ph allyl derivatives of II were investigated and someinteresting results were obtained. The synthesis of 2,3-trans vinylaziridine III wasachieved in seven steps beginning with a Grignard reaction of (4-methoxyphenyl)magnesium bromide with butadiene monoxide. Subsequently, somehighly regioselective ring-opening reactions of III with sulfur-stabilised anionicnucleophiles were achieved. However, in an attempt to synthesise compound I from IIand III, no reaction was observed. This led to the investigation of route B, in which fivemethods for the synthesis of compound IV were investigated. The practical approachdeployed a novel Al-mediated substitution of the 4-tosyl group of the tosyltetrahydropyridine counterpart of IV, prepared from V and III, with a phenylthio group.Chapter 3 provides the experimental details and characterisation data.Imperial Users onl

Aziridine–Metathesis based Approaches to Alkaloid Synthesis

The aim of the project is to synthesise (–)-morphine utilising aziridine and metathesis chemistry. The thesis is divided into three chapters. Chapter 1 provides brief reviews on the subjects of total synthesis of morphine; ringrearrangement metathesis (RRM) and regioselective ring-opening of aziridines. Chapter 2 focuses on the research findings in the past three years. Two routes, A and B, were investigated in attempts to synthesise morphine (Scheme 1). In route A, sulfonyl cyclopentene II was prepared from ring-closing metathesis of a diene precursor, which was synthesised from lithiated cinnamylsulfone and butadiene monoxide. Subsequently, RRM reactions of several α-SO2Ph allyl derivatives of II were investigated and some interesting results were obtained. The synthesis of 2,3-trans vinylaziridine III was achieved in seven steps beginning with a Grignard reaction of (4- methoxyphenyl)magnesium bromide with butadiene monoxide. Subsequently, some highly regioselective ring-opening reactions of III with sulfur-stabilised anionic nucleophiles were achieved. However, in an attempt to synthesise compound I from II and III, no reaction was observed. This led to the investigation of route B, in which five methods for the synthesis of compound IV were investigated. The practical approach deployed a novel Al-mediated substitution of the 4-tosyl group of the tosyl tetrahydropyridine counterpart of IV, prepared from V and III, with a phenylthio group. Chapter 3 provides the experimental details and characterisation data

A Vertical Channel Model of Molecular Communication based on Alcohol Molecules

The study of Molecular Communication(MC) is more and more prevalence, and channel model of MC plays an important role in the MC System. Since different propagation environment and modulation techniques produce different channel model, most of the research about MC are in horizontal direction,but in nature the communications between nano machines are in short range and some of the information transportation are in the vertical direction, such as transpiration of plants, biological pump in ocean, and blood transportation from heart to brain. Therefore, this paper we propose a vertical channel model which nano-machines communicate with each other in the vertical direction based on pure diffusion. We first propose a vertical molecular communication model, we mainly considered the gravity as the factor, though the channel model is also affected by other main factors, such as the flow of the medium, the distance between the transmitter and the receiver, the delay or sensitivity of the transmitter and the receiver. Secondly, we set up a test-bed for this vertical channel model, in order to verify the difference between the theory result and the experiment data. At last, we use the data we get from the experiment and the non-linear least squares method to get the parameters to make our channel model more accurate.Comment: 5 pages,7 figures, Accepted for presentation at BICT 2015 Special Track on Molecular Communication and Networking (MCN). arXiv admin note: text overlap with arXiv:1311.6208 by other author