Author: Jaechul ShimPublisher:
ISBN:
Category :
Languages : en
Pages : 176
Book Description
Total Synthesis of Amaryllidaceae Alkaloids of the 5,11-methanomorphanthridine Type
Author: Jaechul ShimTotal Synthesis of the Crinane-type Amaryllidaceae Alkaloids (+)-maritidine and (+)-oxomaritidine
Author: Lixin DingPublisher:
ISBN:
Category : Alkaloids
Languages : en
Pages :
Book Description
The crinane-type alkaloids are characterized by the presence of the 5,10b-ethanophenanthridine skeleton and represent an important subgroup within the large family of Amaryllidaceae alkaloids, many of which exhibit interesting biological activities. Although they have been the subjects of extensive synthetic investigations over the years, the crinane-type alkaloids have never been synthesized from isoquinoline or substituted isoquinolines, despite the obvious structural relationship between the crinane skeleton and isoquinoline nucleus. In this dissertation, total synthesis of crinane-type alkaloids (+)-maritidine and (+)-oxomaritidine from 6,7-dimethoxyisoquinoline are described. By employing the boron-activated enamine alkylation chemistry developed by the Minter group, isoquinoline and substituted isoquinolines were transformed to 4,4-disubstituted 1,4-dihydroisoquinolines, which then underwent an asymmetric allylation with allylzinc bromide in the presence of a lithiated bis(oxazoline) ligand. Since the resulting homoallylic secondary amine is the key intermediate in the asymmetric total synthesis of crinane alkaloids from isoquinoline, the methodology of this transformation had been investigated and developed. These 1,4-dihydroisoquinolines with a variety of substituents at the C-4 position all underwent the reactions smoothly and enantioselectively. Subsequent conversions including the construction of the crinane skeleton, stereoselective epoxidation and regioselective isomerization of the epoxide to form the allylic alcohol finally gave the pure single enantiomers of (+)-maritidine and (+)-oxomaritidine.
Studies Directed Towards the Total Synthesis of Certain Amaryllidaceae Alkaloids
Author: Cameron J. CowdenPublisher:
ISBN:
Category : Alkaloids
Languages : en
Pages : 440
Book Description
Approaches to the Biogenetically Patterned Synthesis of Amaryllidaceae Alkaloids
Author: Steven William ScottPublisher:
ISBN:
Category : Alkaloids
Languages : en
Pages : 198
Book Description
Total Synthesis of the Lycorenine-type Amaryllidaceae Alkaloid (")-clivonine Via a Biomimetic Ring-switch from a Lycorine-type Progenitor
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
A fully diastereoselective total synthesis of the lycorenine-type Amaryllidaceae alkaloid (")-clivonine is reported via a route that employs for the first time a biomimetic ring-switch from a lycorine-type progenitor, thereby corroborating experimentally the biogenetic hypothesis first expounded for these compounds by Barton in 1960.
Studies Towards the Total Synthesis of Novel Opiate and Amaryllidaceae Alkaloids
Author: Darren HarveyChemoenzymatic Synthesis of Amaryllidaceae Alkaloids and Their C-1 Analogues
Author: Jonathan A. CollinsSynthetic Approaches Towards the Skeleton of the Crinine-type Amaryllidaceae Alkaloids from Isoquinoline and Total Synthesis of (±)-elwesine
Author: Yi ZhangApproaches to the Synthesis of Amaryllidaceae Alkaloids
Author: David Robert DaltonPublisher:
ISBN:
Category : Alkaloids
Languages : en
Pages : 382
Book Description
Investigations in the Synthesis of Amaryllidaceae Alkaloids
Author: Robert R. ZaparanickPublisher:
ISBN:
Category :
Languages : en
Pages : 118
Book Description