N. Satyamurthy

SYNTHESIS AND STEREOCHEMISTRY OF 1-OXA-6-HETERASPIRO[2.5]OCTANES. SINGLE-CRYSTAL ANALYSIS OF 6-PHENYL-1-OXA-6-PHOSPHASPIRO[2.5]OCTANE 6-SULFIDE

Abstract The synthesis of several 1-oxa-6-heteraspiro[2.5]octanes is reported herein for the first time. Stereochemical analysis via NMR studies and a single crystal X-ray diffraction analysis of 6-phenyl-1-oxa-6-phosphaspiro[2.5]octane 6-sulfide have been completed and provide the basis for correlations of structures for other members of the families yet unknown. Epoxidation of cis-2,6-diphenyl-4-thianone with dimethyl-oxosulfonium methylide in DMSO led, surprisingly, to a tertiary alcohol, presumably via ring opening of the expected intermediate epoxide. This is the first example of this type of ring opening in the presence of this base but the reaction time was longer than that normally employed in this process. Since the family members of the parent spiro[2.5]octanes are rare, an X-ray diffraction analysis was performed on 6-phenyl-1-oxa-6-phosphaspiro[2.5]octane 6-sulfide. This analysis revealed a space group of Pna21 with cell dimensions of: a=13.056(3) A, b=14.268(3) A, and c=6.1522(11) A. The phos...

SYNTHESIS OF 3-METHYLENE-1-OXA-8-HETERASPIRO[4.5]DECAN-2-ONES AND 1-OXA-8-HETERASPIRO[4.5]DECAN-2-ONES NOVEL FORMATION AND CRYSTAL STRUCTURE OF 3-[(4-HYDROXY-4-THIANYL)METHYL] - 1-OXA-8-THIASPIRO[4.5]DECAN-2-ONE

Abstract A series of new 3-methylene-1-oxa-8-heteraspiro[4.5]decan-2-ones have been prepared as the first members of the family. Reaction of 1-oxa-6-heteraspiro[2.5]octanes with diethyl malonate, followed by hydrolysis, gave 3-carboxy-1-oxa-8-heteraspiro[4.5]decan-2-ones. The carboxy lactone, upon treatment with diethylamine and formaldehyde followed by sodium acetate and acetic acid, produced α-methyl-eneheteraspiro lactones in good yields and in high purity. Moreover, the carboxy lactones could be decarboxylated smoothly to give l-oxa-8-heteraspiro[4.5]decan-2-ones in good yields. The present method appears to be superior to the widely used Reformatsky reaction since only low yields of the required lactones could be obtained when applied in the work reported herein. An investigation of dilithiated acetic acid as a co-reactant with spiro epoxides of heteracyclohexyl systems was undertaken but rather than the expected γ-lactones, unusual γ-hydroxylactones were obtained. Apparently, the anionic behavior of...

CARBON-PHOSPHORUS HETEROCYCLES. REACTIONS OF THE ENAMINE 1-(1,2,3,6-TETRAHYDRO-1-PHENYL-4-PHOSPHORINYL) PYRROLIDINE P-SULFIDE WITH ACTIVATED ALKENES AND ACID ANHYDRIDES

Abstract The enamine of 1-phenyl-4-phosphorinanone 1-sulfide has been prepared for the first time from the ketone and pyrrolidine in benzene. Crude enamine could be cyanoethylated at carbon. Hydrolysis of the product followed by treatment of the nitrile with aqueous KOH gave the corresponding carboxylic acid. Reduction of this keto acid with NaBH4 in alkaline medium gave the expected carbinol which lactonized spontaneously. Independent synthesis of the keto acid was achieved by adding methyl acrylate to the crude enamine followed by hydrolysis. The crude enamine also reacted with methyl vinyl ketone in dry benzene. Surprisingly, the product was a bicyclic unsaturated ketone which apparently formed via an aldol type condensation (intramolecular) during the hydrolysis of the enamine reaction mixture (hydrolysis was effected with H2O/CH3CO2H/NaO2CCH3). Interestingly, the crude enamine did not react with mesityl oxide or 1-acetyl-1-cyclohexene as only starting material and a polymeric substance could be obtai...

STUDIES ON THE CONFORMATIONS OF 4-N,N-DIMETHYLAMINOTHIANES AND THE CORRESPONDING METHIODIDES. EVIDENCE FROM A SINGLE CRYSTAL X-RAY DIFFRACTION ANALYSIS THAT A TWIST-BOAT CONFORMER EXISTS IN THE SOLID STATE FOR TRIMETHYL-[2,2-DIMETHYL-trans−6-PHENYLTHIAN-r-4-YL]-AMMONIUM IODIDE

Abstract A number of 4-N,N-dimethylaminothianes have been prepared by a reaction of 4-aminothianes with formaldehyde and formic acid. 1H and 13C NMR spectral analysis suggest twist conformations for 2,2-dimethyl-trans-6-phenyl-r-4-N,N-dimethylaminothiane and 2,2-dimethyl-trans-6-(4-chlorophenyl)-r-4-N,N-dimethylaminothiane. Reaction of the tertiary amines with methyl iodide gave the quaternary ammonium iodides. The 1H NMR (270 MHz) spectra of the methiodides in DMSO-d 6 indicated twist conformations for the compounds with axial C[sbnd]N bonds. The spectra also suggested a possible boat conformation for the methiodides of 2,2-dimethyl-trans-6-phenyl-r-4-N,N-dimethylaminothiane and 2,2-dimethyl-trans-6-(4-chlorophenyl)-r-4-N,N-dimethylaminothiane in equilibrium with the twist conformation. Kinetics of quaternization of six epimeric pairs of N,N-dimethylaminothianes with methyl iodide in acetonitrile at 10 ± 0.05°C have been carried out and the causes for the rate differences are discussed in terms of steric...