George Just

A prostaglandin synthesis

The total synthesis of dl-prostaglandin F1 alpha is reported. Prostaglandin E1 and its methyl ester were also obtained. Structural formulas and step by step procedure for all intermediates are presented in the text.

A new method for the conversion of aldehydes to methyl esters using pyridinium dichromate and methanol in dimethylformamide.

Abstract A new method for the conversion of aldehydes to methyl esters using pyridinium dichromate and methanol in DMF is described.

Lead tetraacetate oxidation of aldoximes

Abstract The lead tetraacetate oxidation of aldoximes at low temperature has benn studied. Oxidation of aliphatic and aromatic syn -aldoximes affords nitrile oxides. Aliphatic anti -aldoximes lead to dimeric 1-acetoxy-1-nitroso-alkanes and secondary products. Aromatic anti -aldoximes afford arylaldazine- bis -N-oxides which decompose on heating to nitrile oxides and aldoximes. Mechanisms are proposed which require iminoxy radicals as intermediates in the oxidation of anti -aldoximes, while the oxidation of syn -aldoximes appears to proceed in a concerted manner.

Synthesis and hybridization properties of amide-linked thymidine dimers incorporated into oligodeoxynucleotides

Abstract Thymidine dimers, connected by amide or N-methyl amide linkages, have been prepared. The dimers have each been incorporated three times into normal strands of DNA by solid phase synthesis. Thermal denaturation studies indicated that these modifications caused little or no destabilization of the DNA:RNA duplex.

The synthesis of 11-13-membered diacetylenic and 18-membered tetraacetylenic ring systems

Abstract The synthesis of title compounds is described, starting from o-dibromobenzene. The palladium catalysed coupling of the latter with acetylenes occurred in a step-wise fashion, when no cocatalyst (CuI) was used.

Synthesis of ring A of ambruticin and proof of its absolute stereochemistry

Appropriately derivatized ambruticin was converted by reductive ozonolysis to tetrahydropyran 9c and cyclopropane 12a, which were synthesized from L-arabinose and (R)-Feists acid in an unambiguous...

A short synthesis of (±)-oxetanocin

Abstract The photoadduct 9b of 2-methylfuran and propionyloxyacetaldohyde was transformed in a one-pot reaction to 10d , which gave oxetanocin and its epimer 1α as described 5 .

Derivatized oxopiperazine rings from amino acids

Abstract Two routes for the synthesis of derivatized oxopiperazines, which may act as constrained peptide mimics, are reported. The syntheses employ reductive amination and sulfonamide approaches for generating N-allylic amino acid ester derivatives and utilizing them for assembling the ring systems. An aspartame analog was prepared using this methodology.

The synthesis of a 10-membered benzo-oxadiyne ring

Abstract The synthesis of 10-membered benzo-oxadiyne 12 is described and its thermal stability is compared to that of its carbocyclic analogues 5 and 6.

Syntheses of argentilactone 11 and Goniothalamin 15

Abstract Syntneses of (−)-(5R)-argentilactone 11 and (+)-(5R)-goniothalamin 15 are described starting from olefin 4 .