Perfluoroalkenyl ethers of bile alcohols

Two synthetic routes are presented for the synthesis of bis- and tris-perfluoroalkenyloxy-substituted bile alcohols with an unsubstituted hydroxyl group in the hydrocarbon side chain. The first route involves selective protection of the 24-hydroxyl group of 3α, 7α, 12α, 24-cholan-tetrol followed by the attachment of 3α, 7α, 12α-hydroxyl groups to the perfluoroalkenyloxy linkages and removal of the protecting group. The second pathway is based on the synthesis of the tris-perfluoroalkenyloxy derivative of 3α, 7α, 12α-trihydroxy-chol-22-ene (or bis-perfluoroalkenyloxy derivative of 3α, 12α-dihydroxy-7-deoxy-chol-22-ene), followed by the hydrobaration of the double bond.     

云南植物——露水草中的一种新植物甾酮的分离与分析

云南植物露水草富含植物甾酮类成分。为了研究其中的生物活性成分,采用多种色谱分离方法(氧化铝柱色谱、硅胶柱色谱、常压反相C18柱色谱、制备薄层色谱及反相高效液相色谱等)相结合,从露水草中分离得到一种新植物甾酮。综合一维和二维核磁共振光谱以及电喷雾质谱数据分析,确定该化合物的结构为3β,4α,14α,20R,22R,25-hexahydroxy-5α-cholest-7-en-6-one,为一种较为少见的具有5α-H的植物甾酮。     

A new synthesis of sultams from amino alcohols

The base-mediated cyclization of N,O-dimesylate derivatives of cyclic and acyclic amino alcohols provides a simple access to five- and six-member sultams: isothiazolidine-1,1-dioxides and thiazinane-1,1-dioxides respectively.     

Glycosides from ginseng roots IV. Isolation of new glycosides from ginseng

Summary 1. New glycosides — panaxosides C, D, E, and F — have been isolated from the root of ginseng by partition chromatography.2. The glycosides of ginseng contain genins of two groups: the first consists of the genins of panaxosides A, B, and C, and the second of those of panaxosides D, E, and F. When panaxosides D, E, and F are hydrolyzed, panaxadiol is formed as the main product of the decomposition of the genins.Khimiya Prirodnykh Soedinenii, Vol. 1, No. 2, pp. 82–86, 1965     

High-performance liquid chromatographic separation of bile acids and bile alcohols diastereoisomeric at C-25

The high-performance liquid chromatographic separation of the 25R and 25S diastereoisomers of the bile alcohols 5 beta-cholestane-3 alpha,7 alpha,26-triol and 5 beta-cholestane-3 alpha,7 alpha, 12 alpha, 26-tetrol and the bile acids, 3 alpha,7 alpha-dihydroxy-5 beta-cholestane-26-oic acid and 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestane-26-oic acid is described. A Radial-Pak microBondapak C18 reversed-phase cartridge was used for the separations and elutions were carried out with acetonitrile-water-methanol-acetic acid mixtures. All eight diastereoisomeric compounds showed baseline separation when up to 200 micrograms of the isomeric mixtures were injected into the column and the method can be used for isolation of pure diastereoisomers of these bile acids and bile alcohols.     

Four new 26-aminocholestane-type glycosides from Solanum abutiloides

From the fresh roots of Solanum abutiloides, four new 26-aminocholesteryl glycosides were obtained, and their structures were characterized by analysis of their spectra data, including two-dimensional (2D) NMR spectroscopy. These compounds were regarded as key intermediates in the biogenesis of steroidal alkaloids.     

Four new eremophilane-type alcohols from Cremanthodium helianthus collected in China

Four new eremophilane-type sesquiterpenoid alcohols were isolated from Cremanthodium helianthus collected in China and their structures established on the basis of spectroscopic analyses. All of them had 9-en-8-one partial structures with one more double bond either delta11, delta11(13), or delta7(11). Two of them had a hydroxy group at C-1 position.     

A new and general one-pot synthesis of propargyl alcohols from esters

Intermediates easily prepared by partial reduction of various esters with LDBBA as a reducing agent smoothly react with lithium acetylides to give propargyl alcohols, without isolation of partial reduction intermediates, in good yields (73-83%).     

Marine sterols—II : Asterosterol,a new C26 sterol from Asterias amurensis lütken

Asterosterol, a new marine C₂₆ sterol, was isolated from the asteroid, A. amurensis, and its structure was characterized as 22-trans-24-nor-5α-cholesta-7,22-dien-3β-ol (1). Episterol (9), 22-trans-(24R)-24-methylcholesta-7,22-dien-3β-ol (stellasterol, 3) and 22-trans-cholesta-7,22-dien-3β-ol (7) were also isolated and their structures were confirmed.     

Elimination of beta-thioalkoxy alcohols under Mitsunobu conditions. A new synthesis of conjugated enynes from propargylic dithioacetals

Treatment of propargylic dithiolanes 1 with (n)BuLi followed by a carbonyl electrophile yields the corresponding homopropargylic alcohol 3. Upon treatment with 2 equiv of PPh3 and DIAD, elimination of SR and OH moieties from 3 affords the corresponding olefins 4 in moderate to good yield. The reaction can be considered an alternative of McMurry coupling of two different carbonyl equivalents.     

Short enantioselective syntheses of trans-5-alkylprolines from new functionalized amino alcohols

Amino alcohols, having an enol ether function, cyclized in acidic medium to give quantitatively diastereosomerically pure bicyclic compounds that were transformed in five steps in enantiopure trans-5-alkylproline derivatives.