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The 4,5-diarylated-1H-pyrrole-2-carboxylates 3-8 have each been prepared as hybrids of the potent anti-mitotic agent combretastatin A-4 (1) and the similarly active marine alkaloid lamellarin T (2). The key steps involved selective lithium-for-halogen exchange at C5 within the N-PMB protected 4,5-dibromopyrrole 22 and Negishi cross-coupling of the derived zincated species with the relevant aryl iodide. The ensuing 5-aryl-4-bromopyrrole then engaged in Suzuki-Miyaura cross-coupling with the appropriate arylboronic acid to give the 4,5-diarylated pyrroles 4, 6 and 8. TFA-promoted removal of the N-PMB group within these last compounds then gave the N-unsubstituted congeners 3, 5 and 7. Compounds 3-8 have all been evaluated for their anti-mitotic and cytotoxic properties and two of them, 3 and 5, display useful activities although they are less potent than combretastatin A-4.

Compound 3, representing the tetra-O-methyl ether derivative of structure, 1, assigned to the cytotoxic marine alkaloid halitulin, has been assembled in a convergent manner from the readily available building blocks 5, 6 and 11.

The synthesis of ABE tricyclic analogues 18 of the alkaloid methyllycaconitine 1 is described. The analogues contain the key pharmacophore reputed to be responsible for the biological activity of methyllycaconitine 1, namely, a homocholine motif formed from a tertiary N-ethylamine in a 3-azabicyclo[3.3.1]nonane ring system and a 2-(3-methyl-2,5-dioxopyrrolin-1-yl)benzoate ester side chain. The 3-azabicyclo[3.3.1]nonane ring system 10 was assembled via a double Mannich reaction of ethyl 3-(but-3′-enyl)-2-oxocyclohexane-1-carboxylate 9 with ethylamine and formaldehyde. Attempts to append a B ring to this AE ring system via McMurray coupling of dialdehyde 5 were hampered by the inability to effect conversion of the C-9 ketone 10 to vinyl ether 6. Wittig methylenation of ketone 10 afforded diene 7, however, subsequent attempts to effect double hydroboration–oxidation of diene 7 failed to realise diol 11enroute to the key dialdehyde precursor 5 required for the McMurray coupling. Wacker oxidation of the homoallyl group of 10 afforded methyl ketone 12 which underwent intramolecular aldol condensation to form enone 13. After selective reduction of the ketone and methylation, the resultant methyl ethers 15 underwent reduction of the ester sidechain affording neopentyl substituted alcohols 16. Finally, the 2-(3-methyl-2,5-dioxopyrrolin-1-yl)benzoate ester sidechain was appended by treatment of alcohols 16 with N-(trifluoroacetyl)anthranilic acid followed by fusion of the resultant anthranilates 17 with methylsuccinic anhydride.

The title compound 1 has been prepared, for the first time, in six steps and a completely stereo-controlled fashion from the cis-1,2-dihydrocatechol 3. The starting material is a readily available and enantiopure compound that can be obtained in large quantity ia toluene dioxygenase (TDO) mediated dihydroxylation of iodobenzene.

Compound 1, the structure of which has been assigned to the marine natural product haliclorensin, was prepared by an unambiguous synthetic pathway and subjected to spectroscopic analysis. The derived data do not match those reported for the natural product.

The title compounds 1 and 2, which are effective and specific inhibitors of phosphohexomutases, have been prepared in enantiomerically pure form from toluene. The initial step of the reaction sequence involves enzymatic cis-1,2-dihydroxylation of toluene by E. coli JM109 (pDTG601) to give the cis-1,2-dihydrocatechol 3. The latter compound is then converted, ia a series of chemical oxidation and reduction steps, into compounds 1 and 2. The X-ray crystal structures of the bis-acetonide derivatives 11, 13 and 14 have been determined.

The marine natural products (±)-longamide (1), (±)-longamide B methyl ester (2), (±)-longamide B (3) and (±)-hanishin (4), each of which embodies a pyrroloketopiperazine core, have been synthesised in a concise fashion from pyrrole.

The marine natural products (±)-longamide (1), (±)-longamide B methyl ester (2), (±)-longamide B (3) and (±)-hanishin (4), each of which embodies a pyrroloketopiperazine core, have been synthesised in a concise fashion from pyrrole.

The title compound 1 has been prepared, for the first time, in six steps and a completely stereo-controlled fashion from the cis-1,2-dihydrocatechol 3. The starting material is a readily available and enantiopure compound that can be obtained in large quantity ia toluene dioxygenase (TDO) mediated dihydroxylation of iodobenzene.

The title compounds 1 and 2, which are effective and specific inhibitors of phosphohexomutases, have been prepared in enantiomerically pure form from toluene. The initial step of the reaction sequence involves enzymatic cis-1,2-dihydroxylation of toluene by E. coli JM109 (pDTG601) to give the cis-1,2-dihydrocatechol 3. The latter compound is then converted, ia a series of chemical oxidation and reduction steps, into compounds 1 and 2. The X-ray crystal structures of the bis-acetonide derivatives 11, 13 and 14 have been determined.