Shyamal I. Parekh

A convenient and high yielding procedure for the preparation of isoselenocyanates. Synthesis and reactivity of O-alkylselenocarbamates.

Abstract A high yielding one pot procedure for the preparation of isoselenocyanate from the corresponding formamide is reported. Various aromatic and aliphatic primary amines were employed in order to prepare the isoselenocyanates to establish the generality of the procedure. O-Alkylselenocarbamates of various primary, secondary and tertiary alcohols were synthesized and their stability and comparative reactivity were studied. Radical deoxygenation of the selenocarbamate of a secondary and a tertiary alcohol was accomplished under various conditions.

On the stability and radical deoxygenation of tertairy xanthates.

Abstract Xanthates of tertiary alcohols were isolated and properly characterized. Radical deoxygenation reactions under various conditions to the corresponding alkanes were successfully carried out. Comparative data of various initiatiors and hydrogen atom donors for xanthate deoxygenation are reported.

An efficient synthesis of (-)-dodecahydro-3a,6,6,9a-tetramethylnaphtho[2,1-b]furan from (-)-sclareol

Abstract The title compound 1 was prepared in 74% overall yield (3 steps) from sclareol 2 . The key step involves osmium tetroxide catalysed rearrangement to 4a and b during the oxidative degradation of sclareol.

A REGIOSELECTIVE SYNTHESIS OF METHYL 7-AMINO-3-PHENYLTHIENO-[2,3-b]PYRAZINE-6-CARBOXYLATE

A practical synthesis of methyl 7-amino-3-phenylthieno[2,3-b]pyrazine-6-carboxylate (1) has been achieved via a regioselective synthesis of 3-cyano-5-phenyl-3-phenylthiopyrazine (5a), by condensing 1,1-diethoxyacetophenone with 2,3-diamino-3-phenylthioacrylonitrile.

On the reactions of benzeneseleninic anhydride with monosubstituted hydrazones. Evidence for radical pathways.

Abstract The known oxidation of mono-substituted hydrazones by benzeneseleninic anhydride has been studied using 77 Se and 13 C NMR spectroscopy. The intermediates in the reaction have been identified. Good evidence that certain steps in these reactions are radical in character has been secured.

A Short and Efficient Method for the Preparation of α, p-Dimethylstyrene from Citral (1)

Abstract Acid catalysed cyclization of citral to give α, p-dimethyl styrene using chloranil as an ozidizing agent is reported. The important aspect of this transformation is the dehydration of intermediate piperitenol followed by dehydrogenation to furnish the target compound in 80.5% yield.