摘要:
Di-tert.-butyl dicarbonate having a high purity is prepared by reacting alkali metal tert.-butyl carbonate with methanesulfonyl chloride optionally in the presence of a phase transfer catalyst or an aromatic amine.
摘要:
A method for producing an optically active 2-cyclopenten-4-one-1-ol ester useful as an intermediate for medicines, agricultural chemicals and represented by the general formula (I), ##STR1## wherein R represents a saturated or unsaturated aliphatic hydrocarbon residue which may or may not be substituted with a halogen atom, and a mark * represents an asymmetric carbon,which comprises bringing a 2-cyclopenten-4-one-1-ol ester represented by the general formula ##STR2## wherein R represents a saturated or unsaturated aliphatic hydrocarbon residue which may or may not be substituted with a halogen atom, into contact with an optically active 1,6-diphenyl-2,4-hexadiyne-1,6-diol derivative represented by the general formula (II), ##STR3## wherein R' represents a halogenated phenyl, lower alkylphenyl, naphthyl or tertiary lower alkyl group, and a mark * represents an asymmetric carbon,in an organic solvent to obtain an optically active cyclopentenone ester complex which is a bound product of the optically active 2-cyclopenten-4-one-1-ol ester represented by the foregoing general formula (I) with the optically active 1,6-diphenyl-2,4-hexadiyne-1,6-diol derivative represented by the foregoing general formula (II), and then decomposing the resulting optically active cyclopentenone ester complex.
摘要:
Disclosed are novel optically active benzene derivatives represented by the formula (I): ##STR1## wherein R represents an alkyl or alkoxyalkyl group having 1 to 20 carbon atoms, which group may contain a halogen; Z represents a hydrogen atom or a halogen atom; l and n each represents a number of 0 or 1; and * indicates asymmetric carbon atom, anda process for preparing the above optically active benzene derivative which comprises debenzylating an optically active benzyl derivative represented by the formula (II): ##STR2## wherein, R, Z, l, n and * have the same meanings as defined above, and A represents a hydrogen atom, a lower alkyl group, a lower alkoxyl group or a halogen atom.
摘要:
A process for preparing an optically active cyclopentenone of the formula: ##STR1## wherein R is a hydrogen atom or a lower alkyl group and n is an integer of 4 to 8, which comprises contacting a dl-cyclopentenone ester of the formula: ##STR2## wherein R and n are each as defined above and R' is a lower alkyl group optionally substituted with halogen on an enzyme having a capability of hydrolyzing selectively either one of the d- or l-form isomer in the dl-cyclopentenone ester (II) in an aqueous medium for asymmetric hydrolysis.
摘要:
A process for preparing an optically active 2-substituted or unsubstituted-4-hydroxy-2-cyclopentenone of the formula: ##STR1## wherein R is a hydrogen atom, an allyl group or a propargyl group, which comprises reacting the corresponding 2-substituted or unsubstituted-4-hydroxy-2-cyclopentenone of the formula: ##STR2## wherein R is defined above with a lactone chosen from (1R,5S)-6,6-dimethyl-4-hydroxy-3-oxabicyc lo[3.1.0]hexan-2-one or (1S,5R)-6,6-dimethyl-4-hydroxy-3-oxabicyclo[3.1.0]hexan-2-one in a molar ratio of 1.5 - 2:1 in the presence of p-toluenesulfonic acid or benzenesulfonic acid in the coexistence of an organic solvent under elimination of water as an azeotropic mixture with the organic solvent to obtain a reaction mixture comprising (1R,5S)-6,6-dimethyl-3-oxa-4(R)-[1(R)-4-oxo-2-substituted or unsubstituted-2-cyclopentenyloxy]bicyclo[3.1.0]hexan-2-one or (1S,5R)-6,6-dimethyl-3-oxa-4(S)-[1(S)-4-oxo-2-substituted or unsubstituted-2-cyclopentenyloxy]bicyclo[3.1.0]hexan-2-one of the formula: ##STR3## wherein R is as defined above, of which either one isomer is contained in a considerably larger amount than the other isomer, separating the isom er having the larger content from the reaction mix ture and hydrolyzing the separated isomer to give the optically active 2-substituted or unsubstituted-4-hydrox y-2-cyclopentenone.
摘要:
A process for preparing cyclopentenone derivatives of the formula: ##STR1## wherein R.sup.1 is hydrogen, lower alkyl or lower alkenyl, R.sup.2 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, cycloalkyl, substituted or unsubstituted aryl or substituted or unsubstituted ar(lower)alkyl and A is the residue of a nucleophilic agent from which a hydrogen atom is excluded, which comprises reacting a 3-hydroxy-4-cyclopentenone compound of the formula: ##STR2## wherein R.sup.1 and R.sup.2 are each as defined above with a nucleophilic agent of the formulaA--H (III)wherein A is as defined above.The cyclopentenone derivatives of the formula (I) are useful as pharmaceuticals, agricultural chemicals, perfumes and as intermediates for the preparation of agricultural chemicals, pharmaceuticals and perfumes.
摘要:
A process for producing a compound of the formula: ##STR1## wherein R.sub.1 is a hydrogen atom, an alkyl group or an alkenyl group and R.sub.2 is an alkyl group, an alkenyl group or an alkynyl group, which comprises treating a compound of the formula: ##STR2## wherein R.sub.1 and R.sub.2 are each as defined above and R is a hydrogen atom or a lower alkyl group in the presence of an acidic substance and water.
摘要:
A method for producing an optically active 2,2-dimethylcyclopropanecarboxylic acid useful as an intermediate for dehydropeptidase I inhibitors, medicines and agricultural chemicals, which comprises reacting an optically active diphenylethylamine represented by the formula, ##STR1## wherein R.sub.1 and R.sub.2 are each a hydrogen atom or a lower alkyl group, with 2,2-dimethylcyclopropanecarboxylic acid in a solvent to achieve the optical purification of said acid.
摘要:
2-Cyclopentenone esters of the formula: ##STR1## wherein R.sup.1 is hydrogen, lower alkyl or lower alkenyl, R.sup.2 is lower alkyl, lower alkenyl, lower alkynyl, or cycloalkyl, cycloalkenyl or substituted or unsubstituted aryl and R.sup.3 is hydrogen or lower alkyl are prepared in high yields by reacting the corresponding racemic or optically active 4-cyclopentenone of the formula: ##STR2## wherein R.sup.1 and R.sup.2 are each as defined above and R.sup.3 is hydrogen or acyl with at least one lower aliphatic carboxylic acid and/or metal or amine salts thereof.
摘要:
Bisphenoxy carboxylic acid derivatives useful as an antiarteriosclerosis agent with good absorbability and low toxicity, which are novel compounds represented by the general formula, ##STR1## wherein R.sub.1 and R.sub.2 represent hydrogen atoms or lower alkyl groups and A preresents ##STR2## (wherein in case R.sub.3 is a hydrogen atom, R.sub.4 represents an amino-lower-alkyl group, an N-lower-alkylaminoalkyl group, a heterocyclic group, or a heterocyclic group-substituted alkyl group; or R.sub.3 and R.sub.4 may join through an intermediary hetero atom to form a heterocyclic group and if said hetero atom is a nitrogen atom, this nitrogen atom can bear a lower alkyl group as a substituent) or ##STR3## (wherein R.sub.5 represents a hydrogen atom, a hydroxyalkyl group or a derivative thereof, and R.sub.6 represents a hydroxyalkyl group or a heterocyclic group; or R.sub.5 and R.sub.6 may join to form a cyclic group, or may join through another intermediary hetero atom to form a heterocyclic group and if said hetero atom is a nitrogen atom, this nitrogen atom can bear a lower alkyl group as a substituent).