Philip W. Le Quesne

Quararibea metabolites. 3. Total synthesis of (±) - funebral, a rotationally restricted pyrrole alkaloid, using a novel Paal-Knorr reaction☆

Abstract The total synthesis of (±) - funebral 5 , a sterically crowded, rotationally restricted pyrrole alkaloid, has been achieved by means of a new variation of the Paal-Knorr synthesis, employing titanium isopropoxide.

Further alkaloidal constituents of the leaves of Rhazya stricta

Abstract Studies on the alkaloidal constituents of the leaves of Rhazya stricta have resulted in the isolation and structure elucidation of rhazimal (16-formylstrictamine), rhazimol (deacetylakuammiline), rhazinol (a hydroxymethyl analogue of strictamine). Two more new alkaloids stricticine and strictine have also been isolated.

Total synthesis of (+) pseudophrynaminol

The first synthesis of (+) pseudophrynaminol, a unique pyrrolo [2,3b] indole recently isolated from the Australian frog Pseudophryne coriacea, is described.

Novel synthesis of 2-fluoroestradiol from 19-Cortestosterone: Biomimetic oxidative defluorination to 2-hydroxyestradiol

A new, short synthetic route to 2-fluoroestradiol from 19-nortestosterone is described which gives the target compound in an approximately 25% overall yield. Oxidative defluorination of 2-fluoroestradiol to 2-hydroxyestradiol via treatment with Frémys salt/iodide ion is reported. This process is regarded as biomimetic with respect to cytochrome P-450-dependent oxidative defluorination.

Quararibea Metabolites. 2.1 Efficient Synthetic Approaches to (±)-(2S, 3S, 4R)-γ-Hydroxyisoleucine, the Characteristic Quararibea Amino Acid

Abstract The characteristic metabolites of Quararibea funebris are based on (2S, 3S, 4R)-γ-hydroxyisoleucine, a hitherto rare amino acid. Two new stereoselective and efficient syntheses of this compound are described; one is based on Claisen chemistry and the other on addition reactions to the butenolide ring of β-angelicalactone.

Total Synthesis of Magnolamide

The first total synthesis of magnolamide, a new alkaloid from Magnolia coco, has been achieved using the titanium (IV) isopropoxide-mediated Paal-Knorr synthesis of the core pyrrole system.

Total synthesis of the cyclodepsipeptide ionophore pithomycolide

Abstract The total synthesis of pithomycolide 1 , a structurally unique ionophoric depsipeptide from the fungus Pithomyces chartarum , is described.