Gareth M. Davies

Reactivity studies in the shikimic acid series

Abstract The regio- and stereo-selective epoxidation of methyl 3,4-dihydrobenzoate has been investigated and a synthesis of racemic methyl 6α-fluoroshikimate from the acetonide of methyl 3,4-dihydro-3α,4α-cyclohexenoate is described. This work has importance for the preparation of 6-substituted shikimic acid derivatives useful in the study of the biosynthesis of aromatic amino acids via the shikimic acid pathway.

The Pd(0)-catalysed coupling reactions of 2-(tri-n-butylstannyl)-3,4-dihydrofuran and -5,6-dihydropyran.

The palladium(0) catalysed reaction of dihydropyranyl and dihydrofuranylstannanes offers an attractive route to the sythesis of 2-vinylhydropyrans and -furans.

The shikimate pathway. Part 8. Synthesis of (−)-3(R)-amino-4(R),5(R)-dihydroxy-1-cyclohexene-1-carboxylic acid: The 3(R)-amino analogue of (−)-shikimic acid

Abstract The first successful method for the introduction of nitrogenous functionality at C-3 of the shikimate nucleus has been developed and has allowed the synthesis of (−)-3(R)-amino-4(R),5(R)-dihydroxy-1-cyclohexene-1-carboxylic acid [the 3(R)-amino analogue of (−)-shikimic acid] in seven steps from the parent acid.

Aryl coupling through borate complexes with ethanolamine.

Abstract The scope and limitations of aromatic coupling by the action of N-bromosuccinimide on stable diarylethanolamine borate salts are disclosed. The procedure is an excellent, regiospecific procedure for the coupling of furyl and thienyl residues to each other or to aromatic rings in mild conditions and without scrambling.

The shikimate pathway. Part 9. Halogenation at C-3 of the shikimate nucleus☆

Abstract The use of (−)-shikimic acid as starting material in the syntheses of a series of C-3 halogenated derivatives including the analogous 3α- and 3β-fluoro and 3β-chloro acids is described together with the first stereospecific synthesis of (−)-3-epi-shikimic acid directly from the parent acid.

Reactivity studies in the shikimic acid series: the synthesis of racemic methyl 6α-fluoroshikimate

Abstract The regio- and stereo-selective epoxidation of methyl 3,4-dihydrobenzoate derivatives has been investigated. Perbenzimidic acid leads only to epoxides formed at the Δ1,2 bond. More electrophilic reagents such as MCPBA also give products of this type, as well as epoxides formed through attack at the Δ5,6 bond. Reactions of the 3,4-dihydrobenzoates with thiophenate anion have been undertaken as a means of protecting the Δ1,2 bond and thence controlling the regioselectivity of epoxidation. A synthesis of racemic methyl 6α-fluoroshikimate has been achieved through the ring-opening of an epoxide of methyl 3,4-dihydro-3,4-isopropylidenedioxybenzoate.

Synthesis of methyl (−)-homogabaculinate and a carba analogue of 5-enolpyruvylshikimic acid

Abstract The synthesis of (±)-3-[1-carboxy-3α,4α-dihydroxycyclohex-1-en-5β-yl]-2-methylenepropionic acid, a carba analogue of 5-enolpyruvylshikimic acid from methyl (±)-homogabaculinate is described. In addition, both enantiomers of methyl homogabaculinate have been obtained from the Diels Alder reaction of 1- tert -butoxy-carbonyl-1,2-dihydropyridine and the N -acryloyl derivative of Oppolzers bornane 10,2-sultam.

A preparation of 3,3-bis(tri-n-alkylstannyl)acrylates and related systems

Abstract A convenient synthesis of 3,3-bis(tri-n-alkylstannyl)acrylates via an addition-elimination sequence is described.

Synthesis of (±)-homogabaculine and (±)-homoshikimic acid

Abstract Syntheses of homogabaculine and homoshikimic acid are described utilising the base mediated ring opening of the cycloadducts of methyl acrylate and N -carbamoyl-1,2-dihydropyridines.

Synthesis of (3R)- and (3S)-Fluoro-(4R,5R)-dihydroxy-1-cyclohexene-1-carboxylic acids: The (3R)- and (3S)-fluoro analogues of (−)-shikimic acid

Abstract (3 R )- and (3 S )-Fluoro-(4 R ,5 R )-dihydroxy-1-cyclohexene-1-carboxylic acids (the (3 R )- and (3 S )-fluoro analogues of (−)-shikimic acid) have been synthesised from (−)-shikimic acid via an intermediate epoxide (a fungal metabolite from Chalara microspora ) that underwent acid catalysed hydrolysis to afford the first stereospecific synthesis of (−)-3- epi -shikimic acid.