β-Stannylpropionaldehyde. A versatile cyclopropane building-block

Various functional group-substituted cyclopropanes were prepared in good yield starting from β-tributylstannylproprionaldehyde via homoallylstannanes or γ-hydroxypropylstannanes.     

Synthesis of (−)-Warburganal and 4α-methoxycarbonyl congener from 1-abietic acid

Natural warburganal (1b) and 4α-methoxycarbonyl congener (1a) were efficiently synthesized from 1-ãbietic acid ($\text{2}$) by selective and oxidative     

Synthesis of monomers that expand on polymerization. Synthesis and polymerization of 2,6,7-trioxabicyclo[2.2.2]octanes with phenyl groups

2,6,7-Trioxabicyclo[2.2.2]octanes with phenyl group were prepared to obtain monomers which expand on polymerization. 1-Phenyl-4-ethyl-2,6,7-trioxabicyclo[2.2.2]octane (I) could expand 0.2% during polymerization at a temperature slightly higher than the melting point. 1,4-Diphenyl-2,6,7-trioxabicyclo[2.2.2]octane (II) also expanded as much as 1.4% on polymerization. Further, the hydrolysis of 2,6,7-trioxabicyclo[2.2.2]octanes with p-substituted phenyl groups were investigated to estimate the stability in water.     

Preparation and properties of methyl(cyclopentadienyl)thalium derivatives

The preparation of the compound CH₃(C₅H₅)TIX [where X = OCOCH₃, OCOC₂H₅, OCO-i-C₃H₇, tropolonate and 4-isopropyltropolonate] is described and their chemical behaviours as well as their PMR and IR spectra are discussed.     

Copolymerization of unsaturated spiro ortho esters with maleic acid derivatives

The formation of charge-transfer (CT) complexes of unsaturated spiro ortho esters such as 2-methylene-1,4,6-trioxaspiro[4.4]nonane(I) and 2-methylene-1,4,6-trioxaspiro[4.6]undecane(II) with maleic acid derivatives such as maleic anhydride (Manh), dimethyl maleate (DMM), and N-ethyl maleimide (NEM) was ascertained by ultraviolet (UV) and nuclear magnetic resonance (NMR) spectroscopy. The stoichiometries of these complexes were estimated as 1:1. The determination of their equilibrium constants (K) was attempted by using the Hanna-Ashbough equation with NMR spectroscopy. Although K values for I-DMM and II-DMM were specified as 0.266 and 0.336 L/mol, respectively, those for the other systems could not be obtained but were assumed to be negligible small (K ? 1). Copolymerization of these systems which was carried out without an initiator determined that spontaneous copolymerization occurs in all cases but that the copolymerization rates of I-DMM and II-DMM systems are slow. The systems in which Manh or DMM was used as an acceptor monomer gave the alternating copolymers at various monomer to feed ratios. The terpolymerizaton of the I–Manh–DMM system established that DMM takes little part in giving the alternating copolymers I and Manh. Consequently, it was assumed that the reactivity of the CT complex monomer is dependent on the contribution of the dative structure to CT complex.     

Preparation of novel tricyclic ring systems containing the pyridazinone ring

Novel tricyclic ring systems, irmdazo[3,4-d]pyridazino[4,5-b][1,4]thiazines 3 , imidazo[2,1-b]pyridazino[4,5-e][1,3,4]thiadiazines 15 and 18 were prepared by the reaction of 5-amino-4-chloropyridazin-3(2H)-ones 1 and 5(4)-(1-methylhydrazino)-4(5)-chloropyridazin-3(2H)-ones 13 (16) with isothiocyanates 2 and 7 .     

Preparation and properties of novel palladium compounds containing a thiomethoxymethyl group

Oxidative addition of chloromethyl methyl sulfide to Pd(Ph₃P)₄ provided a good yield of Pd(Ph₃P)₂(CH₂SCH₃)Cl (I) whose ¹H NMR and molecular weight data showed that dissociation of either the phosphine or the chloride ligand occurs in CH₂Cl₂ solution. In accord with such equilibria, repeated crystallization of I from CH₂Cl₂ and Et₂O gradually removed the triphenylphosphine set free in these solvents to give the monomeric complex. Pd(Ph₃P)(CH₂SCH₃)Cl (III), while treatment of 1 with NH₄PF₆ in CH₂Cl₂ and acetone gave the cationic complex [Pd(Ph₃P)₂(CH₂SCH₃]PF₆ (II),¹H NMR spectra of II and III are discussed in terms of a three-membered chelate structure arising from coordination of sulfur with palladium     

Viologens that plunder electron from solid reducing agent. Reduction of aryl ketones by zinc powder in the presence of propyl viologen as an electron transfer catalyst

It was found that viologen (propyl viologen) acted as an Electron Transfer Catalyst (ETC) in the reduction of aryl ketones with zinc powder. α-Diketones undertook the two-electron reduction to obtain the corresponding benzoins in good yields and aromatic ketones could one-electron reduced selectively to give the corresponding pinacols.     

119Sn chemical shifts in seven-coordinate organotin compounds

The FT NMR studies revealed that ¹¹⁹Sn chemical shifts in seven-coordinate organotin compounds are more than 100 ppm upfield from those in six-coordinate analogues.