Rachel D. Marwood

Synthesis of adenophostin A

Abstract The natural product and potent agonist of the d - myo -inositol 1,4,5-trisphosphate receptor, adenophostin A, was synthesised from adenosine and d -glucose using efficient methodology. The synthetic material was equipotent with naturally occurring adenophostin A in evoking Ca 2+ release from the intracellular stores of permeabilised cells.

Synthesis of adenophostin A and congeners modified at glucose

A convergent route is described to the super-potent 1D-myo-inositol 1,4,5-trisphosphate receptor agonist adenophostin A (2) and analogues 5 and 7, in which the glucose bisphosphate unit is replaced by corresponding xylose bisphosphate and mannose bisphosphate units respectively. Adenosine was converted into its 2′,3′-O-p-methoxybenzylidene derivative 8ab, which was selectively N6-dimethoxytritylated by a transient protection method. 5′-O-Benzylation followed by reductive acetal cleavage gave, after separation from its 3′-O-p-methoxybenzyl isomer, the versatile glycosyl acceptor 5′-O-benzyl-N6-dimethoxytrityl-2′-O-p-methoxybenzyladenosine 13. Coupling of 13 with selectively protected glucopyranosyl, xylopyranosyl or mannopyranosyl dimethyl phosphites gave the required 3′-O-α-pyranosyl adenosine derivatives. Acidic hydrolysis gave corresponding N6-unprotected triols which were phosphitylated using bis(benzyloxy)(diisopropylamino)phosphine and imidazolium triflate without further N6-protection. Deprotection gave the target trisphosphates 2, 5 and 7. Synthetic adenophostin A (2) was identical with a sample of natural material in all respects. Analogues 5 and 7 will be useful for structure–activity studies on the adenophostins.

A disaccharide polyphosphate mimic of 1D-myo-inositol 1,4,5-trisphosphate

A concise route from D-glucose and D-ribose to a potent sugar polyphosphate second messenger mimic related to adenophostin A is described; a role for the adenine base of the adenophostins is suggested.

Convergent synthesis of adenophostin A analogues via a base replacement strategy

The first totally synthetic base-modified analogues of the natural product and potent D-myo-inositol 1,4,5-trisphosphate receptor agonist adenophostin A were efficiently synthesised from D-xylose and D-glucose using methodology employing base and surrogate base addition to a common disaccharide intermediate.