Search results for "stemona"

showing 2 items of 2 documents

Conformationally Locked Pyramidality Explains the Diastereoselectivity in the Methylation of trans-Fused Butyrolactones

2020

A stereoselectivity model inspired by the total synthesis of stemona alkaloids is developed to explain why enolate-derived 3,4-fused butyrolactones are methylated with a preference for syn alkylation. The model shows how conformational locking present in nonplanar enolate structures favors syn over anti methylation, due to less significant structural distortions in the syn pathway. The developed model was also successfully used to rationalize selectivities of previously documented methylation reactions. peerReviewed

StemonaLetterisomeriaStereochemistrytransition states010402 general chemistry01 natural sciencesBiochemistryenolatesheterocyclic compoundsPhysical and Theoretical Chemistryorgaaniset yhdisteetkemialliset reaktiotbiology010405 organic chemistryChemistryorganic chemicalsOrganic ChemistryselectivityTotal synthesisMethylationbiology.organism_classification0104 chemical sciencesalkaloiditchemical structureorganic reactionsStereoselectivityOrganic Letters
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Synthetic studies on 1-azabicyclo[5.3.0]decane alkaloids

2018

The first chapter introduces the reader to the concept of natural product total synthesis and its importance to chemistry, other sciences, and society. The second chapter reviews the chemistry of natural products containing 1-azabicyclo[5.3.0]decane motifs. This bicyclic motif and the natural products related to it, have been a continuous source of synthetic inspiration over the last decades. The second chapter of the thesis reviews the strategies and tactics developed. The third chapter covers the author’s total synthesis of stemoamide, a 1-azabicyclo[5.3.0]decane motif containing alkaloid. Additionally, two diastereomers of stemoamide were synthesized, allowing their structural reassignme…

kemiallinen synteesialkaloiditstemonanatural productscephalotaxustotal synthesisalkaloidsluonnonaineetkokonaissynteesi
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