Simon B Bedford

Synthesis of water-soluble prodrugs of the cytotoxic agent Combretastatin A4

Water-soluble phosphate and glycine carbamate prodrugs of the cytotoxic agent Combretastatin A4 (1) have been prepared. The phosphate prodrug was degraded slowly in plasma at 37°C. The degradation was accelerated by the addition of alkaline phosphatase.

Iodoetherification of homoallylic alcohols : A stereoselective approach to tetrahydrofurans

Abstract Iodoetherification of homoallylic alcohols proceeds efficiently and with high levels of stereoselection by a 5-endo-trig process when anhydrous acetonitrile is used as the solvent.

Iodine-induced cyclisations of (E)- and (Z)-3-hydroxy-5-alkenoates : stereoselective approaches to trisubstituted tetrahydrofurans

Iodoetherification of the (Z)-3-hydroxy-5-alkenoates 4 leads exclusively to the hydroxytetrahydrofurans 5 whereas similar cyclisations of the corresponding (E)-isomers [10, 13 and 15] give largely the iodo-tetrahydrofurans [11, 14 and 16].

Stereoselection in iodolactonisations of 3-silyloxy-5-alkenoic acids

Iodolactonisations of (Z)- or (E)-3-silyloxy-5-alkenoic acids [1 and 7] both lead to transdisubstituted valerolactones [6 and 8], which differ only in the stereochemistry of the iodine substituent.

Formative peer and self feedback as a catalyst for change within science teaching

Feedback to students is vital for effective learning; however, it is a relatively under- researched area in the UK. This study sought to use new and more effective methods of formative feedback to students within the context of Chemistry teaching in order to facilitate student learning. Emphasis was placed on the use of Student Directed Assessment, and in particular, the use of Student Self and Peer-Assessment. During semester 2 of the 2005-06 academic year, a cohort of some 100 Chemistry students and 33 Natural Sciences students attended a series of problem-based workshops designed to test Self and Peer Assessment methods. Results show that both Peer and Self Assessment were preferred over Tutor Assessment. Whilst Peer Assessment was viewed as helping to learn more on specific topics, Self Assessment was perceived as having a didactic value as they learned from their own mistakes. [Chem. Educ. Res. Pract., 2007, 8 (1), 80-92]

Model studies of the overall 5-endo-trig iodocyclization of homoallylic alcohols

Overall 5-endo-trig iodocyclizations of homoallylic alcohols, with a range of substitution patterns, leading to β-iodotetrahydrofurans are usually highly efficient and stereoselective when carried out in anhydrous acetonitrile in the presence of sodium hydrogen carbonate. Such cyclizations, which are not exceptions to Baldwin’s rules as they are electrophile-driven, appear to proceed via a well-ordered chair-like transition state. The iodine can be replaced by hydroxy, acetoxy and azide groups.

Embedding external referencing of standards into higher education: collaborative relationships are the key

Abstract External referencing of assessment and students’ achievement standards is a growing priority area within higher education, which is being pressured by government requirements to evidence outcome attainment. External referencing benefits stakeholders connected to higher education by helping to assure that assessments and standards within courses are appropriate and comparable among institutions. External referencing takes many forms, which have different resourcing requirements, outcomes, and operational strengths and challenges. This paper describes the External Referencing of Standards (ERoS) approach developed, tested and adopted by a university consortium. ERoS draws on the strengths of existing methodologies to produce an evolved model that is effective, efficient, transparent and open, capability building and sustainable. The model enables participants to communicate directly and construct peer relationships, and findings suggest this is a significant design strength. The process facilitates capability building, such that participants garnered insights valuable to enact quality assurance and enhancement of existing courses, and fosters connections that facilitate collaboration and peer-learning. ERoS successfully used open source collaborative tools to review work samples, which can be used to benchmark costed systems.

Leading the way: changing the focus from teaching to learning in large subjects with limited budgets

To lead positive change in the teaching practice of teams that service large numbers of diverse students from multiple degree programs provides many challenges. The primary aim of this study was to provide a clear framework on which to plan the process of change that can be utilized by academic departments sector wide. Barriers to change were reduced by adapting and utilizing Kotters principals of change specifically by creating a sense of urgency and defining a clear goal designed to address the problem. Changing attitudes involved training staff in new teaching and learning approaches and strategies, and creating a collaborative, supportive team‐based teaching environment within which the planned changes could be implemented and evaluated. As a result senior academics are now directly involved in delivering sections of the face‐to‐face teaching in the new environment. Through promoting positive change we enabled deeper student engagement with the theoretical concepts delivered in lectures as evidenced by favorable student evaluations, feedback, and improved final exam results. A collaborative team‐based approach that recognizes the importance of distributed leadership combined with a clearly articulated change management process were central to enabling academics to design, try, and evaluate the new teaching and learning practices. Our study demonstrates that a concerted focus on “change management” enabled teaching team members to adopt a major shift in the teaching and learning approach that resulted in measurable improvements in student learning.

On the stereoselection of iodolactonizations of 3-silyloxyalk-5-enoic acids

Iodolactonizations of 3-triisopropylsilyloxyalk-5-enoic acids (10b and 12) proceed by way of common transition-state geometry 23, in which the silyloxy group is positioned axially, presumably due to hydrogen bonding with the carboxylic acid group.

Compounds with six-membered heterocyclic rings containing one or more atoms from groups 3A, 4A or 5A together with nitrogen

This chapter discusses the chemistry of six-member heterocyclic compounds containing at least one nitrogen atom and one ‘unusual’ atom such as boron, gallium, silicon, germanium, tin, lead, phosphorus, arsenic or antimony. The nomenclature used in the chapter commonly uses the word endings inine to denote a six-member heterocyclic ring, which is fully unsaturated or –inane to denote fully saturated. The precedence of heteroatom numbering is oxygen > sulfur > nitrogen > phosphorus > silicon > germanium > boron > gallium. The chapter attempts to use a systematic nomenclature, unless the names are in common usage, where the both names appear in the section heading. The structure of reactions and synthesis for the compounds and the chemistry involved are discussed and provided for the reader.