Calvin L. Stevens

Pyridinium dichromate oxidation. Modifications enhancing its synthetic utility

An improved procedure is described for extremely rapid and efficient oxidation of alcohols, by adding a small quantity of anhydrous acetic acid (AcOH) to pyridinium dichromate (PDC) and freshly activated molecular sieve powder in CH2Cl2 at room temperature.

The synthesis of phosphorylated 3′-amino-3′-deoxythymidine and 5′-amino-5′-deoxythymidine

3′-Amino-3′-deoxythymidine 5′-phosphate (6) and 5′-amino-5′-deoxythymidine 3′-phosphate (10) were prepared as analogues of the corresponding naturally occurring nucleotides.

Modified Pyridinium Dichromate Oxidation, A Facile Synthesis of the Key 3-Keto Sugar Intermediate for L-Daunosamine

Abstract An efficient procedure is described for the large scale preparation of the key 3-keto sugar intermediate in the synthesis of L-daunosamine, using readily available and relatively inexpensive chemicals, under mild conditions. A simple and effective work up, based on mechanistic considerations, is also presented.

Stereospecific synthesis of β-dglucopyranosyl (dihydrogen phosphate)

Abstract Stereospecific opening of the Brigl anhydride, namely, 3,4,6-tri- O -acetyl-1,2-anhydro-α- d -glucopyranose, by hydrogen (dibenyl phosphate) afforded 3,4,6-tri- O -acetyl-β- d -glucopyranosyl (dibenzyl phosphate). This was subjected to debenzylation, followed by deacetylation, to furnish β- d -glucopyranosyl (dihydrogen phosphate), isolated as the crystalline brucine salt having physical constants in agreement with those reported in the literature.

Proof of structure and synthesis of α-D-glucopyranosyl (dihydrogen phosphate)☆

The reaction of 3,4,6-tri-O-acetyl-2-O-trichloroacetyl)-β-D-glucopyranosyl chloride with silver (dibenzyl phosphate) yielded 3,4,6-tri-O-acetyl-2-O-(trichloroacetyl)-α-d-glucopyranosyl (dibenzyl phosphate) (2a). Hydrolysis of the trichloroacetyl group of 2a, followed by acetylation, afforded 1,3,4,6-tetra-O-acetyl-β-D-glucopyranose 2-(dibenzyl phosphate). However, when 2a was subjected to debenzylation followed by deacetylation, it furnished α-D-glucopyranosyl (dihydrogen phosphate), which was isolated as the crystalline brucine salt having physical constants identical with those reported in the literature.