Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.773300
Title: Stereoselective total synthesis of lupin alkaloids
Author: Lyu, Xiang
ISNI:       0000 0004 7960 7138
Awarding Body: University of Southampton
Current Institution: University of Southampton
Date of Award: 2018
Availability of Full Text:
Access from EThOS:
Full text unavailable from EThOS. Please try the link below.
Access from Institution:
Abstract:
A highly anti-selective formal imino-aldol methodology has been developed and applied to asymmetric total synthesis of five alkaloids, including (+)-lupinine, ()-epitashiromine, (-)-epilamprolobine, (+)-isosophoridine and (+)-sparteine. This method combined an imino-aldol reaction and anti-alkylation, with a variety of (S)-p-tolylsulfinimines, to give anti-products with high diastereoselectivity (dr >10:1). Absolute stereochemical determination of the anti-product was proved by the synthesis of (+)-lupinine and ()-epitashiromine in 17% and 23% overall yields respectively. The first total synthesis of the tetracyclic lupin alkaloid (+)-isosophoridine has been completed in 10 steps in 9% overall yield. The target molecule was assembled with excellent control of contiguous stereocenters employing an anti-selective formal imino-aldol reaction and N-acyliminium cyclisation as key steps. As a part of our studies towards (+)-isosophoridine, we performed the first total synthesis of the tricyclic alkaloid (-)-epilamprolobine. In addition, based on the anti-selective methodology and good understanding of N-acyliminium cyclisation chemistry, a total synthesis of (+)-sparteine has been achieved in 16 linear steps and 1.6% overall yield, which employed a cross metathesis to assemble the allyl silane present in the N-acyliminium precursor.
Supervisor: Brown, Richard Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.773300  DOI: Not available
Share: