Wayne K. Anderson

A Simplified Procedure for the Efficient Conversion of Aromatic Aldehydes into Esters

Abstract A mild, efficient conversion of aromatic aldehydes into their corresponding methyl (or ethyl) esters was achieved by treatment with manganese dioxide and sodium cyanide in methanol (or ethanol) but without the use of acetic acid.

Laser annealing of laser assisted molecular beam deposited ZnO thin films with application to metal-semiconductor-metal photodetectors

We report on the effect of postdeposition laser annealing of undoped zinc oxide (ZnO) thin films grown by laser assisted molecular beam deposition. Hall-effect measurements show that some undoped ZnO films change from n type with mobility values in the range of 200cm2V−1s−1 to p-type material with mobility value of 73cm2V−1s−1, after laser annealing. The photoconductive behavior was clearly seen on the laser-annealed samples, with values of 0.28mΩ−1. The structural and optical properties of the films were improved with laser annealing as shown by scanning electron microscopy, x-ray photoelectron spectroscopy analysis, and photoluminescence measurement. All of the nonlaser and laser annealed samples showed near-band emission at ∼3.3eV. Metal-semiconductor-metal photodetectors were fabricated from the films.

A facile selective acylation of castanospermine

Abstract A facile selective acylation on the 6-hydroxyl group of the polyhydroxylated indolizidine alkaloid castanospermine, ( 1 ), has been achieved by the in situ use of a preformed dibutyl organotin derivative.

Synthesis of Novel Indole Analogues of Mycophenolic Acid as Potential Antineoplastic Agents

The expedient synthesis of three novel indole analogues, 2a–c, of mycophenolic acid is described, which involved as the key steps both the Et2O·BF3 catalyzed amino-Claisen rearrangement of N-allylindoline to 7-allylindoline and the ortho ester Claisen rearrangement of the allylic alcohol 12 to the methyl ester 14. The installation of the substituents at the C-3 position in 2b and 2c was accomplished via Vilsmeier formylation and subsequent oxidation–aminolysis or oxidation–methoxylation. The synthetic approach described possesses general usefulness. The analogue 2b showed significant, reproducible antitumor activity.

Total synthesis of of 4-acetyloxymethyl-1,6,9-trimethyl-1,-9-diazaanthracene-2,5,8,10-tetraone, a nybomycin acetate analogue.

Abstract 4-Acetyloxymethyl-1,6,9-trimethyl-1,9-diazanthracene-2,5,8,10-tetraone 2 (a potential metabolite of nybomycin) was prepared in thirteen steps with a hetero Diels-Alder reaction as a key step.

AN EFFICIENT SYNTHESIS OF 5,7-DIMETHOXY-4-METHYLPHTHALIDE, A KEY INTERMEDIATE IN THE SYNTHESIS OF MYCOPHENOLIC ACID

Abstract An efficient synthetic pathway is described for 5,7-dimethoxy-4-methylphthalide, a key intermediate in the synthesis of mycophenolic acid and its analogues. The procedure starts from methyl 3,5-dimethoxybenzoate and involves five simple steps to give phthalide 3 in 55% overall yield.

Facile Preparation of Substituted Allenic Esters via the Ortho Ester Claisen Rearrangement

Abstract Five substituted allenic esters were prepared in good yields through the ortho ester Claisen rearrangement of primary and secondary propargyl alcohols.

A Synthesis of γ-Ketocarboxylic Acids and its Application in the Preparation of Benzo [B]Furans

Abstract The aldol addition-pinacol rearrangement sequence starting with 1,2-bis(trimethylsilyloxy)cyclobutene and a ketal or acetal provides facile entry into a series of substituted 1,3-cyclopentadiones.2 This, combined with the known propensity for 1,3-diketones to undergo cleavage reactions, affords a useful sequence for the synthesis of γ-ketocarboxylic acids: Application of this sequence is demonstrated in a new synthesis of 2,3-dihydrobenzo [b] furan (ergo, benzo[b] furan).

The Synthesis of Amidine Acetals as Intermediates for the Preparation of Naturally Occurring Cyclic Amidine Antibiotics

Abstract Regioselective 1,3-dipolar cycloaddition of (phenylsulfonyl)nitrile oxide to acrolein dimethylacetal gave the isoxazole 3. Nucleophilic displacement of the phenylsulfonyl moiety followed by reductive N-O bond cleavage gave the amidine acetal 6.

A Facile Synthesis of an (E)-4-Methyl-4-Hexenoic Acid Substituted Pyridine Analogue of Mycophenolic Acid

Abstract An (E)-4-methyl-4-hexenoic acid substituted pyridine analogue, 2, of mycophenolic acid has been synthesized from 6-methyl-2-pyridine-carboxaldehyde in 6 steps via a Claisen rearrangment.