摘要:
A novel single-pot trialkylsilyl trifluoromethanesulfonate (R.sub.3 Si-OTf) mediated process produces derivatives of 4-aza 3-keto steroids at the .alpha.-methylenic carbon through electrophilic substitution. These derivatives are useful in the preparation, through elimination of the substituent on the .alpha.-methylene carbon, of .DELTA.-1 olefin 4-aza 3-keto steroids which are potent inhibitors of 5-.alpha. reductase.
摘要:
A novel, facile, and specific process for .alpha.-iodinating or .alpha.-brominating the .alpha.-methylenic carbon of a straight chain, branched chain, or cyclic secondary amide, such as a lactam or an azasteroid, comprises reacting the amide with trialkylsilyl-X (R.sub.3 Si--X), where X is Br, I, or Cl, and R is methyl, ethyl, or n-propyl, in the presence of I.sub.2 or Br.sub.2. The .alpha.-iodo- or .alpha.-bromo-amide is useful for making the .alpha.,.beta.-unsaturated amide through dehydrohalogenation.
摘要:
A process utilizes the tetrazole functional group to direct lithiation at the ortho position of a phenyltetrazole and generate a nucleophilic aryllithium species which then undergoes reaction with an electrophile to generate a 2-substituted 1-(tetrazol-5-yl)benzene. The process is useful in the production of intermediates in the synthesis of angiotensin II antagonists. This novel process is a more cost effective and versatile route for the large-scale preparation of these key intermediates.
摘要:
A unique process for preparing certain (2R-trans)hexahydroaroquinolizines, especially (2R-trans)-N-[2-(1,3,4,6,7,12b-hexahydro-2'-oxospiro[aro-[2,3-a]-quinolizine-2,4'-imidazolidin]-3'-yl)ethyl)-methanesulfonamide from (2R-trans)-N-[2-[(2-cyano-(1,3,4,6,7,12b-hexahydro-aro-[2,3-a]quinolizin-2-yl)amino]ethyl]methanesulfonamide is described.
摘要:
A process for selectively debrominating polybromoalkyl aryl ketones and polybromoalkyl heteroaryl ketones is disclosed. The process comprises contacting an alpha-polybrominated ketone with an alkali metal sulfite in the presence of a C2-C6 alkylcarboxylic acid to obtain a selectively mono-debrominated product.
摘要:
A process for preparing cis-(1S,2R)-indanediol is disclosed. The process comprises (A) fermenting a culture medium containing a yeast strain selected from the group consisting of Trichosporon cutaneum MY 1506 (ATCC 74440) and mutants thereof and 1,2-indanedione to form cis-(1S,2R)-indanediol; and (B) recovering cis-(1S,2R)-indanediol from the culture medium. A process for preparing (1S)-amino-(2R)-indanol from the recovered cis-(1S,2R)-indanediol via the Ritter reaction is also disclosed.
摘要:
This invention discloses novel intermediates and novel process for their preparation where said intermediates are useful for the preparation of 5-oxygenated derivatives (T) of lovastatin and analogs thereof at the 8-acyl side chain and 6-position of the polyhydronaphthyl ring. Said derivatives of lovastatin (T) and analogs thereof are useful in treating hypercholesterolemia and are disclosed in the U.S. Pat. No. 4,963,538. ##STR1##
摘要:
The present invention relates to an improved process for the in situ preparation of diisopinocampheylchloroborane which comprises reacting sodium borohydride and boron trichloride with .alpha.-pinene. The diisopinocampheylchloroborane thus obtained may be used, without isolation, to reduce prochiral ketones to their corresponding alcohols in high optical purity.
摘要翻译:本发明涉及一种二异蒎烷基氯代硼烷的原位制备改进方法,其包括使硼氢化钠和三氯化硼与α-蒎烯反应。 这样得到的二蒎烯yl yl chlor chlor ob or or may。。。。。。。,,,。。。。。。。。。。。。。
摘要:
A unique process for preparing certain (2R-trans)hexahydroaroquinolizines, especially (2R-trans)-N-[2-(1,3,4,6,7,12b-hexahydro-2'-oxospiro[aro-[2,3-a]-quinolizine-2,4'-imidazolidin]-3'-yl) ethyl)-methanesulfonamide from (2R-trans)-N-[2-[(2-cyano-(1,3,4,6,7,12b-hexahydro-aro-[2,3-a]quinolizin-2-yl)amino]ethyl]methanesulfonamide is described.