An effective total synthesis and assignment of the absolute configuration of the architecturally challenging compound (+)-scholarisine A has been achieved via a 20-step sequence. Highlights include a reductive cyclization involving a nitrile and an epoxide, a modified Fischer indole protocol, a late-stage oxidative lactonization, and an intramolecular cyclization leading to the indolenine ring system of (+)-scholarisine A.
(-)-Akagerine (1) was synthesized in an efficient and stereocontrolled fashion from the readily available (1S,2R)-cyclohexenedimethanol monoacetate 4. Key steps were the cleavage of the C(17)/C(18) bond of 14a and the regio- and stereoselective cyclization of the dialdehyde 16 to give the tetracyclic skeleton of akagerine.
First enantiodivergent Baeyer–Villiger oxidation by recombinant whole-Cells expressing two monooxygenases from Brevibacterium
作者:Marko D Mihovilovic、Florian Rudroff、Bernhard Müller、Peter Stanetty
DOI:10.1016/s0960-894x(03)00137-9
日期:2003.4
MicrobialBaeyer-Villigeroxidations of representative mesomeric ketones with recombinant Escherichia coli cells expressingtwomonooxygenases from Brevibacterium were investigated. The two enzymes displayed enantiodivergent biotransformations on an array of structurally diverse substrates, allowing access to some key lactone intermediates in natural compound synthesis.
Access to the Akuammiline Family of Alkaloids: Total Synthesis of (+)-Scholarisine A
作者:Gregory L. Adams、Patrick J. Carroll、Amos B. Smith
DOI:10.1021/ja3111626
日期:2013.1.9
The planning and implementation of an enantioselective total synthesis of (+)-scholarisine A is presented. Key tactics employed include a novel cyclization, consisting of a nitrile reduction coupled with concomitant addition of the resultant amine to an epoxide; a modified Fischer indolization; an oxidative lactonization of a diol in the presence of an indole ring; and a late-stage cyclization to complete the caged ring scaffold. The development of a possible "retro-biosynthetic" approach to other members of the akuammiline alkaloid family is also described.
Family Clustering of Baeyer-Villiger Monooxygenases Based on Protein Sequence and Stereopreference
作者:Marko D. Mihovilovic、Florian Rudroff、Birgit Grötzl、Peter Kapitan、Radka Snajdrova、Joanna Rydz、Robert Mach