Abstract: A simple and efficient method is proposed for the preparation of a &bgr;-lactam compound such as 1-phenyl-4-ethoxy-2-azetidinone which can be produced by mixing an isocyanate compound such as phenyl isocyanate and a vinyl ether compound such as ethyl vinyl ether and heating the mixture at a moderate temperature under a superatmospheric pressure of up to 12000 atmospheres.

Abstract: Disclosed is a novel, high molecular weight aliphatic polyester having excellent mechanical strengths such as breaking strain and containing a copolymer structure with 3-alkoxy-1,2-propane diol and a method of producing the aliphatic polyester in an industrially advantageous manner. The aliphatic polyester is a biodegradable high molecular weight aliphatic polyester having an ester structure derived from 3-alkoxy-1,2-propane diol.

Abstract: Disclosed is a novel, high molecular weight aliphatic polyester having excellent mechanical strengths such as breaking strain and containing a copolymer structure with 3-alkoxy-1,2-propane diol and a method of producing the aliphatic polyester in an industrially advantageous manner. The aliphatic polyester is a biodegradable high molecular weight aliphatic polyester having an ester structure derived from 3-alkoxy-1,2-propane diol.

Abstract: An aliphatic copolyester having a plurality of first: ester units of the formula: —CO—[R1]t—CO—O—R2—O— wherein R1 represents a divalent aliphatic group, R2 represents a divalent aliphatic and t is an integer of 0 or 1, and a plurality of second ester units of the formula: wherein R1 and t are as defined above and R3 represents an aliphatic group. The molar ratio of the first ester unit to the second ester unit is 90:10 to 99.9:0.1. The copolyester is produced by reacting an aliphatic diester with an aliphatic glycol and with a monoacylated glycerin under ester exchanging conditions.

Abstract: A process of producing a polyester or copolyester, wherein at least one cyclic lactone of the following formula (I): wherein n is an integer of 1-4 provided that n is not 2 when only one cyclic lactone is used, is polymerized under a pressure of at least 200 MPa in the absence of any catalyst or in the presence of a metal-free polyesterification catalyst.

Abstract: Disclosed is a novel .beta.-lactam compound, a 7-substituted-2-oxa-7-azabicyclo?3.2.0!heptan-6-one represented by the general formula ##STR1## in which R is an alkyl, cycloalkyl, aryl, halogen-substituted aryl or alkaryl group, having usefulness as an intermediate for the synthesis of various biologically active compounds. The compound can be prepared by the reaction of an isocyanate compound RNCO, R being the same as above, and 2,3-dihydrofuran, preferably, under pressurization up to 2000 atmospheres or higher.

Abstract: A novel and simple method is proposed for the synthetic preparation of an N,N-disubstituted .beta.-ketothioamide compound represented by the general formulaR.sup.1 R.sup.2 N--CS--CH.sub.2 --CO--R.sup.3,in which R.sup.1 and R.sup.2 are each a monovalent hydrocarbon group or each a divalent hydrocarbon group jointly forming a cyclic structure together with the nitrogen atom and R.sup.3 is a hydrogen atom, a monovalent hydrocarbon group or a divalent hydrocarbon group forming a cyclic structure jointly with R.sup.1, R.sup.1 being a divalent hydrocarbon group and R.sup.2 being a monovalent hydrocarbon group. The method comprises:(a) mixing an N,N-disubstituted amide compound represented by the general formulaR.sup.1 R.sup.2 N--CO--R.sup.3,and a bis(trialkylsilyl)thioketene compound represented by the general formula(R.sub.3 Si).sub.2 C.dbd.C.dbd.

Abstract: Disclosed is a method for the preparation of a .beta.-thiolactam compound, i.e. a 7-substituted-2-oxa-7-azabicyclo [3.2.0]-heptan-6-thione, represented by the general formula ##STR1## in which R is an alkyl or aryl group, having usefulness as an intermediate for the synthesis of various biologically active compounds. The compound can be prepared by the reaction of an isothiocyanate compound R--NCS, R being the same as above, and 2,3-dihydrofuran, preferably, under pressurization up to 2000 atmospheres or higher at an elevated temperature.

Abstract: Disclosed is a novel .beta.-lactam compound, a 7-substituted-2-oxa-7-azabicyclo[3.2.0]heptan-6-one represented by the general formula ##STR1## in which R is an alkyl, cycloalkyl, aryl, halogen-substituted aryl or alkaryl group, having usefulness as an intermediate for the synthesis of various biologically active compounds. The compound can be prepared by the reaction of an isocyanate compound RNCO, R being the same as above, and 2,3-dihydrofuran, preferably, under pressurization up to 2000 atmospheres or higher.

Abstract: There is disclosed a method for producing 2,6-bis(disubstituted amino)-1,3,5-thiadiazine-4-one compounds represented by formula (I). The method comprises reacting an N,N-disubstituted cyanamide represented by formula (II) with carbonyl sulfide represented by formula (III) under a high pressure. Formula (I) ##STR1## wherein R.sub.1 and R.sub.2 each represent an alkyl group or R.sub.1 and R.sub.2 may bond together to form a ring, Formula (II) ##STR2## wherein R.sub.1 and R.sub.2 each have the same meanings as in formula (I), Formula (III)S.dbd.C.dbd.O.