Timothy Charles Walsgrove

A new synthesis of the GPIIb/IIIa receptor antagonist SB-214857-A

A new synthesis of lotrafiban SB-214857-A is reported. The key steps are the preparation of racemic (4-methyl-3-oxo-2,3,4,5-tetrahydro-1H-benzo[e][1,4]diazepin-2-yl)-acetic acid methyl ester from 2-nitrobenzyl alcohol, a resolution using an immobilised lipase enzyme and a palladium-catalysed aminocarbonylation reaction.

A sequential stereocontrolled cyclopropane ring formation and semi-pinacol rearrangement

Treatment of an unsaturated 2,3-epoxy alcohol with SnBr 4 leads to a stereoselective formation of a cyclopropane ring, and an α-ketol unit as part of a subsequent ring expansion.

A convergent rgiospecific route to the aklavinone ring system

Abstract A convergent regiospecific route to the aklavinone (II) ring system is described.

A facile total synthesis of racemic aklavinonet

Abstract A convergent total synthesis of aklavinone, based on the annelation reaction of cyanophthalide addition to an enone as the key step, was accomplished.

Indole-fused tetraazacyclooctadecanes: double-helical macrocycles

Transannular hydrogen bonding stabilizes a left-handed double helical conformation in the tryptophan-derived tetraazacyclooctadecane 1 both in solution and the solid state, whereas the analogous tryptamine-derived macrocycle 2 shows less tendency towards intramolecular hydrogen bonding and does not exist as a helix in the crystal. Azamacrocycles 1 and 2 are synthesized by a novel method and their secondary structure analysed by NMR spectroscopy, circular dichroism and X-ray diffraction. Molecular modelling does not account for the conformational differences between 1 and 2.