Facile synthesis of two diastereomeric indolizidines corresponding to the postulated structure of alkaloid 5,9E-259B from a Bufonid toad (Melanophryniscus)

A short synthesis of the postulated structure for indolizidine alkaloid 259B with the hydrogens at C5 and C9 entgegen has been achieved with complete control of stereochemistry at C5. Both diastereoisomers at C8 were obtained, but neither proved to be the natural product. The comparison of the mass and FTIR spectral properties of the synthetic compounds to those of the natural material strongly suggest that the gross structure is correct and that the difference may be a branch in the C5 alkyl side-chain. The GC-retention times of the two synthetic compounds were markedly longer than that of the natural 5,9E-259B.

A Synthesis of (S)-(-)-Umbelactone and Related α,β-Butenolides

The development of an asymmetric route for the synthesis of alpha,beta-butenolide building blocks, starting from commercially available D-mannitol, is described. The devised route was applied to a synthesis of the (S)-(–)-enantiomer of the antiviral natural product umbelactone, together with the construction of other synthetically useful lactone structures.

Chemoenzymatic synthesis of the carbasugars carba-beta-L-galactopyranose, carba-beta-L-talopyranose and carba-alpha-L-talopyranose from methyl benzoate

The cis-dihydrodiol metabolite from methyl benzoate has been used as a synthetic precursor of carba-beta-L-galactopyranose, carba-beta-L-talopyranose and carba-alpha-L-talopyranose. The structures and absolute configurations of these carbasugars were determined by a combination of NMR spectroscopy, stereochemical correlation and X-ray crystallography.

Preaching to Princes: John Burgess and George Hakewill in the Royal Pulpit

This article examines a previously unnoticed link between the Puritan John Burgess and the Calvinist conformist George Hakewill. In 1604 Burgess preached a court sermon so outspoken and critical of James I’s religious policy that he was imprisoned. Nearly twenty years later, however, Hakewill chose to incorporate extended passages from Burgess’s sermon into the series of sermons, King David’s vow (1621), preached to Prince Charles’s household. This article considers why Burgess’s sermon became so resonant for Hakewill in the early 1620s and also demonstrates how Hakewill deliberately sought to moderate Burgess’s strident polemic. In so doing the article provides important new evidence for the politically attuned sermon culture at Prince Charles’s court in the early 1620s and also suggests how, as the parameters for clerical conformity shifted in the latter years of James’s reign, Calvinist conformists found a new appeal in the works of moderate Puritans. I

Synthesis and Reactions of Enantiopure Substituted Benzene cis-Hexahydro-1,2-diols

Enantiopure cis-dihydro-1,2-diol metabolites, obtained from toluene dioxygenase-catalysed cis-dihydroxylation of six monosubstituted benzene substrates, have been converted to their corresponding cis-hexahydro-12-diol derivatives by catalytic hydrogenation via their cis-tetrahydro-1,2-diol intermediates. Optimal reaction conditions for total catalytic hydrogenation of the cis-dihydro-1,2-diols have been established using six heterogeneous catalysts. The relative and absolute configurations of the resulting benzene cis-hexahydro-1,2-diol products have been unequivocally established by X-ray crystallography and NMR spectroscopy. Methods have been developed to obtain enantiopure cis-hexahydro-1,2-diol diastereoisomers, to desymmetrise a meso-cis-hexahydro-1,2-diol and to synthesise 2-substituted cyclohexanols. The potential of these enantiopure cyclohexanols as chiral reagents was briefly evaluated through their application in the synthesis of two enantiomerically enriched phosphine oxides from the corresponding racemic phosphine precursors.