Synthesis of macrocyclic dilactones by cyclization of sulfonium salts
摘要:
An efficient method for the formation of macrocyclic dilactones via cyclization of (omega-carboxyalkyl)diphenylsulfonium salts 3 containing an ester linkage under mild conditions is described. These sulfonium salts 3 were cyclized in the presence of cesium carbonate under high-dilution conditions to give 11- to 16-membered dilactones 4 in good yields. The cyclization of sulfonium salt 22 was successfully carried out for the synthesis of 11-membered dilactonic pyrrolizidine alkaloid, 13,13-dimethyl-1,2-didehydrocrotalanine 23.
Cosmetic and dermatological preparations comprising an isoflavone content and the use of isoflavones for producing cosmetic and dermatological preparations for reducing the sebum content of the skin
申请人:——
公开号:US20040170655A1
公开(公告)日:2004-09-02
Use of isoflavones for producing preparations for reducing sebum production and/or for establishing a normal sebum homeostasis, as well as for the prophylaxis and treatment of greasy hair and dandruff.
异黄酮用于生产减少皮脂分泌和/或建立正常皮脂平衡的制剂,以及预防和治疗油腻发质和头皮屑。
Cosmetic and dermatological preparations comprising a content of a hop extract or hop-malt extract and the utilization of a hop extract or hop-malt extract for producing cosmetic and dermatological preparations for reducing the sebum contents of the skin
申请人:——
公开号:US20040141938A1
公开(公告)日:2004-07-22
Use of a hop extract or a hop-malt extract for producing preparations for reducing sebum production and/or for establishing a normal sebum homeostasis, as well as for the prophylaxis and treatment of acne, blemished skin, greasy hair and dandruff.
[EN] COMPOUNDS FOR QUENCHING REACTIVE METAL CATALYTIC SPECIES REMAINED IN POLYESTER POLYOL RESINS, QUENCHING PROCESS AND ITS APPLICATION IN POLYURETHANE PRODUCTION THEREIN<br/>[FR] COMPOSÉS POUR LA DÉSACTIVATION D'ESPÈCES CATALYTIQUES MÉTALLIQUES RÉSIDUELLES DANS DES RÉSINES À BASE DE POLYOL DE POLYESTER, PROCÉDÉ DE DÉSACTIVATION ET SON APPLICATION DANS LA PRODUCTION DE POLYURÉTHANNE
申请人:BAYER MATERIALSCIENCE AG
公开号:WO2011018161A1
公开(公告)日:2011-02-17
A method to produce polyester polyol resin with quenched or deactivated residual catalytic metal ion species therein is disclosed. Feature organic compounds of macrocyclic ethers, alkyl and/or aryl substituted phoshine, alkyl and/or aryl substituted phosphine oxides, alkyl and/or aryl substituted phosphine sulfides, alkyl and/or aryl substituted quaternary ammonium halide salts are used as effective deactivation compounds to quench the unfavorable activities of residual metal ion species originated from the metal Lewis acid catalyst(s) during a continuous two-step process of polyester polyol production. Two deactivation processes denoted as the pre-deactivation process and the post-deactivation process are also disclosed. The polyester polyol resin product of present invention may be used as active-hydrogen atoms containing raw material for successive production of diverse two-component based polyurethane with decreased -OH/-NCO adduction rates, better color appearances and improved product qualities.
Synthesis of macrocyclic dilactones by cyclization of sulfonium salts
An efficient method for the formation of macrocyclic dilactones via cyclization of (omega-carboxyalkyl)diphenylsulfonium salts 3 containing an ester linkage under mild conditions is described. These sulfonium salts 3 were cyclized in the presence of cesium carbonate under high-dilution conditions to give 11- to 16-membered dilactones 4 in good yields. The cyclization of sulfonium salt 22 was successfully carried out for the synthesis of 11-membered dilactonic pyrrolizidine alkaloid, 13,13-dimethyl-1,2-didehydrocrotalanine 23.