Studies Towards the Synthesis of the Core of Endiandric Acid H
In the presence of a CuBr·SMe2 catalytic system, a very simple and efficient approach for the synthesis of the key precursor of the core of endiandric acids starting from the readily and abundantly available 3-butyn-1-ol in five linear steps with an overall yield of 40% was developed.
The endiandric acid cascade. Electrocyclizations in organic synthesis. 3. "Biomimetic" approach to endiandric acids A-G. Synthesis of precursors
Als Vorstufen fur eine biornimetische Synthese der Endiandrinsauren A-G werden die Ester (IVa) und (IVb) synthetisiert: Die Kondensationsprodukte (IIIa) bzw. (IIIb) aus den Komponenten (I) und (II) werden mit Persaure zu den Sulfoxiden (IIIc) bzw. (IIId) oxidiert, deren Thermolyse zu (IVa) bzw. (IVb) (jeweils 1 :l-Gemisch der geometrischen Isomeren an der neu gebildeten Doppelbindung) fuhrt.
Preparation courses for a medical admissions test: effectiveness contrasts with opinion
Objectives  The Undergraduate Medicine and Health Sciences Admissions Test (UMAT) is used to rank applicants for admission to many medical schools. This study aimed to determine the effects of preparation courses on UMAT performance and on students’ perceptions of their performance.