Selective Protection of 1,2- and 1,3-Diols via Acylative Cleavage of Cyclic Formals
摘要:
An efficient two-step method for the differential functionalization of 1,2- and 1,3-diols, involving regioselective cleavage of five- and six-membered cyclic formals with acetyl chloride followed by conversion of the resulting chloromethyl ether acetate 1 to an alkoxymethyl ether acetate (2), has been developed. When applied to unsymmetrically substituted cyclic formals, the differential functionalization sequence is highly selective and produces an alkoxymethyl ether acetate having the acetate at the less hindered center and the acetal moiety at the more hindered center. Removal of either protecting group affords a selectively monoprotected diol: for the case of an unsymmetrical diol, removal of the acetate gives a product selectively protected with an acetal group at the more hindered hydroxyl.
Thienopyridine compounds, their production and use
申请人:——
公开号:US20010001104A1
公开(公告)日:2001-05-10
The compound of the present invention possesses excellent gonadotropin-releasing hormone antagonizing activity, and is useful for preventing or treating sex hormone-dependent diseases, e.g., sex hormone-dependent cancers (e.g., prostatic cancer, uterine cancer, breast cancer, pituitary tumor), prostatic hypertrophy, hysteromyoma, endometriosis, precocious puberty, amenorrhea syndrome, multilocular ovary syndrome, pimples etc, or as a pregnancy regulator (e.g., contraceptive), infertility remedy or menstruation regulator.
[EN] FUSED RING COMPOUNDS AND USE THEREOF<br/>[FR] COMPOSÉS CYCLIQUES CONDENSÉS ET UTILISATION DE CEUX-CI
申请人:TAKEDA PHARMACEUTICAL
公开号:WO2009125873A1
公开(公告)日:2009-10-15
The present invention aims to provide a glucokinase activator useful as a pharmaceutical agent such as an agent for the prophylaxis or treatment of diabetes, obesity and the like. The present invention provides a glucokinase activator containing a compound represented by the formula (I): wherein each symbol is defined in the specification, or a salt thereof or a prodrug thereof.
[EN] AGENT FOR PREVENTING OR TREATING NEUROPATHY<br/>[FR] AGENT POUR LA PRÉVENTION OU LE TRAITEMENT DE NEUROPATHIE
申请人:TAKEDA CHEMICAL INDUSTRIES LTD
公开号:WO2004039365A1
公开(公告)日:2004-05-13
The present invention provides an agent for preventing or treating neuropathy having superior action and low toxicity. This agent comprises a compound represented by the formula:wherein ring A is a 5-membered aromatic heterocycle containing 2 or more nitrogen atoms, which may further have substituent(s);B is an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group;X is a divalent acyclic hydrocarbon group;Z is -O-, -S-, -NR2-, -CONR2- or -NR2CO- (R2 is a hydrogen atom or an optionally substituted alkyl group);Y is a bond or a divalent acyclic hydrocarbon group;R1 is an optionally substituted cyclic group, an optionally substituted amino group or an optionally substituted acyl group, provided that when the 5-membered aromatic heterocycle represented by ring A is imidazole, then Z should not be -O-, or a salt thereof.
A novel method for an efficient regioselective acetylation of carbohydrates and diols in aqueous solution is described. Treatment of substrates with 1-acetylimidazole, and tetramethyl-ammonium hydroxide (TMAH) in water under mild conditions gave highly regioselective acetylation for primary hydroxyl groups. This discovery provides an eco-friendly way for selective acetylation of non-protected glycosides