Abstract: Butyrolactone derivatives having the formula ##STR1## wherein R is a C.sub.4 -C.sub.10 alkyl group, which have an appetite-regulating effect, a process for their production, and compositions containing them, are disclosed.

Abstract: There is here disclosed a ladder polysilane represented by the general formula (I): ##STR1## wherein n is a positive integer, and R is a halogen atom, a hydrogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an aryl group or an alkoxy group having 20 or less carbon atoms, and the alkyl, alkenyl, aryl or alkoxy group may contain a functional group such as --COOH, --SO.sub.3 H, --NH.sub.2, --NO.sub.2, --NCO, --F, --Cl, --BR, --I or --OH. In addition, a method for preparing the aforesaid ladder polysilane is also disclosed here.

Abstract: A thermosetting composition which is capable of affording a heat-resisting, condensed polynuclear aromatic hydrocarbon resin and which includes:a raw material containing one or more condensed polynuclear aromatic compounds having at least three condensed benzene rings;a crosslinking agent containing an aromatic compound having at least two hydroxymethyl or halomethyl groups; andan acid catalyst. The raw material may be, for example, a coal pitch or petroleum pitch.

Abstract: A dimethylphenysilylmethylpolysilane is prepared by condensating 1,1-dichloro-1,2,2-trimethyl-2-phenyldisilane in the presence of an alkali metal or alkali earth metal, in an aprotic solvent. This polymer is a viscous liquid which has a weight average molecular weight in the range of from 5,000 to 500,000 and a narrow molecular weight distribution, and has various uses as electroconductors, photoresist and optical information recording materials.

Abstract: A 1,2,2-trimethyl-1-phenylpolydisilane is prepared by condensating 1,2-dichloro-1,2,2-trimethyl-1-phenyldisilane in the presence of an alkali metal or alkali earth metal, in an aprotic solvent. This polymer is a viscous liquid which has a weight average molecular weight in the range of from 5,000 to 500,000 and a narrow molecular weight distribution, and has various uses as electroconductors, photoresist and optical information recording materials.

Abstract: This invention relates to 1,2-dichloro-1,2,2-trimethyl-1-phenyldisilane expressed by the chemical formula (II),Cl(CH.sub.3).sub.2 SiSi(CH.sub.3)(C.sub.6 H.sub.5)Cl.This invention further relates to a method for producing 1,2-dichloro-1,2,2-trimethyl-1-phenyldisilane by reacting phenyl lithium with 1,1,2-trichloro-1,2,2-trimethyldisilane expressed by the chemical formula (III),Cl(CH.sub.3).sub.2 SiSi(CH.sub.3)Cl.sub.2.This invention still further relates to a method for producing 1,2-dichloro-1,2,2-trimethyl-1-phenyldisilane by reacting 1,1,2-trichloro-1,2,2-trimethyldisilane with phenylmagnesium halide expressed by the general formula (IV), C.sub.6 H.sub.5 MgX (X=halogen atom) in the presence of a cobalt catalyst.

Abstract: This invention relates to a novel asymmetric 1,1-dichloro-1,2,2-trimethyl-2-phenyldisilane expressed by the chemical formula (I), (C.sub.6 H.sub.5) (CH.sub.3).sub.2 SiSi(CH.sub.3)Cl.sub.2.This invention further relates to a method for producing 1,1-dichloro-1,2,2-trimethyl-2-phenyl disilane by reacting 1,1,2-trichloro-1,2,2-trimethyl disilane expressed by the chemical formula (III), Cl(CH.sub.3).sub.2 SiSi(CH.sub.3)Cl.sub.2 with phenyl magnesium halide expressed by the general formula (IV), C.sub.6 H.sub.5 MgX (X=halogen atom) in the presence of a transition metal (except for cobalt) catalyst.