Donald C. Dittmer

Telluride-mediated stereospecific conversion of racemic E-allylic alcohols to homochiral Z-allylic alcohols; transposition of primary and secondary allylic alcohols via glycidol derivatives

Abstract Racemic trans -secondary allylic alcohols can be converted to homochiral cis -secondary allylic alcohols by means of a telluride-mediated transposition reaction applied to the homochiral glycidol obtained from a Sharpless kinetic resolution. (+)-Linalool is obtained in >95% enantiomeric excess from geraniol, an example of a transposition of a primary allylic alcohol to a homochiral tertiary alcohol.

A tellurium-triggered domino reaction for the synthesis of a 1-substituted-3-vinyl-1,3-dihydroisobenzofuran

Abstract Telluride ion reacts with an oxiranemethanol toluenesulfonate in toluene under phase-transfer conditions to give an allylic alkoxide anion that is trapped by addition to an adjacent α,β-unsaturated ester to yield a furan derivative. Use of a non-racemic oxiranemethanol tosylate gives two furan diastereomers in a ratio of 56:44.

Alkenes from cyclic sulfates and thionocarbonates of 1,2-diols via tellurium chemistry

Treatment of 1,2-diol cyclic sulfates (1,3,2-dioxathiolane 2,2-dioxides) with telluride ion, generated in situ by reduction of the element, yields alkenes rapidly (10 min- 2 h) under mild conditions (0 °C to room temperature). The reaction is stereospecific, e.g. meso-2,3-diphenylethane 2,3-diol → cis-stilbene; d,l-2,3-diphenylethane-2,3-diol → trans-stilbene. Unsaturated mannose and ribose derivatives have been obtained, and diethyl (-)-tartrate gives diethyl fumarate. The reaction may be performed with 0.1 equiv or less of elemental tellurium in the presence of a stoichiometric amount of reducing agent. Reaction of telluride ion with cyclic thionocarbonates (1,3-dioxolane-2-thiones) of meso- and d,l-1,2-diphenylethane-1,2-diol yields cis- and trans-stilbene, respectively.

Tellurium in the “no-solvent” organic synthesis of allylic alcohols

Abstract Elemental tellurium can be reduced by rongalite (HOCH2SO2Na·2H2O)-KOH in the solid phase by application of ultrasound or by microwave irradiation. Without solvent, the organic substrate (eg sulfonate ester of an oxiranemethanol) is added with further sonication or irradiation to yield the desired organic product (eg allylic alcohols) and elemental Te which may be recycled. Phase-transfer conditions (water-toluene) also are satisfactory.

Functional group modification via organotellurium chemistry. Synthesis of allyl alcohols from chloromethyloxiranes.

Abstract Treatment of 2-substituted-2-chloromethyloxiranes with telluride ion gives 2-substituted allyl alcohols, presumably through an epitellurlde intermediate.

A catlaytic tellurium process for the transposition of allylic hydroxyl groups and carbon-carbon double bonds

Abstract As little as 0.1 molar equivalent of elemental tellurium in combination with excess (up to 3 molar equivalents) reducing agent (HOCH 2 SO 2 Na·2H 2 O, NaBH 4 , or LiEt 3 BH) effects the telluride-ion mediated transposition of allylic hydroxyl groups and carbon-carbon double bonds that proceeds via the epoxy tosylate. The workup is much more convenient than when a molar equivalent of tellurium is used.

Tellurium: Use in the synthesis of allylic amines from 5-hydroxymethyl-2-oxazolidinones

Abstract Non-racemic or racemic allylic amines are obtained by treatment of sulfonate esters of 5-hydroxymethyl-2-oxazolidinones with telluride ion.

2-Substituted-4-hydroxymethyltellurophenes from acetylenic epichlorohydrins and sodium telluride

Abstract 2-Substituted-4-hydroxymethyltellurophenes and acetylenic allyl alcohols (enynols) are products from the action of sodium telluride on acetylenic epichlorohydrins. Variation in the degree of reduction of tellurium to telluride ion has a dramatic effect on the ratio of tellurophene to allyl alcohol, either of which may be obtained as the major product.

SYNTHESIS AND PROPERTIES OF SOME STABLE, NEW THIETES (THIACYLOBUTENES)

Abstract 3-Phenyl-, 3-β-naphthyl-, 3-α-thienyl- and 3-α-furylthietes have been prepared. They are considerably more stable than simple, alkyl-substituted thietes. Cobalt cyclopentadienyl complexes of 2-phenylpropenethial and its S-methyl derivative have been obtained, the latter exemplifying a new ligand.

Tellurium-triggered formation of racemic and non-racemic allylic amines from aziridinemethanol derivatives

Abstract Sharpless epoxidation, aminohydroxylation, and aziridination procedures provide substrates for the tellurium-triggered synthesis of racemic and non-racemic allylic amines under phase-transfer conditions.