Peter Gärtner

Enantioselective addition of organometallics to aldehydes using camphor derived chiral 1,4-aminoalcohols as ligands

Abstract (+)-Camphor derived enantiomerically pure 1,4-aminoalcohols have been used as ligands in the addition reactions of n -BuLi and n -BuMgBr to benzaldehyde and in the reaction of diethylzinc with benzaldehyde and hexanal. All chiral secondary alcohols were obtained in good chemical yields and enantioselectivities were up to 87% ee in the addition of diethylzinc.

Aminoalkohole, 1. Mitt.: Ein Verfahren zur Synthese enantiomerenreiner 1,2-Aminoalkohole miterythro-Konfiguration

SummaryThe synthesis of both enantiomers of norephedrine and norisoephedrine is described to present a method for the preparation of enantiomerically pure branched 1,2-aminoalcohols. In a one pot reaction enantiomerically pure cyanohydrins bearing an acetal protective group are subjected to Grignard-reaction followed by addition of lithium aluminum hydride. After deprotection the target compounds are obtained.

New camphor derived chiral ligands for asymmetric synthesis

Abstract New enantiomerically pure 1,4-diols and 1,4-aminoalcohols have efficiently been prepared in one and two steps, respectively, from a commercially available camphor derived exo fused lactone. Using sterically hindered amines, an aldol addition of two lactone molecules was observed and the stereochemistry of the products was determined by X-ray crystallography.

[1,2]-Wittig rearrangement of acetals. Part 2: The influence of reaction conditions

Abstract Acetals of seven alcohols with (+)-camphor derived enantiomerically pure 7,8,8-trimethyl-4,7-methanobenzofuran-2-ol were subjected to different reaction conditions favorable for a [1,2]-Wittig rearrangement. Results with regard to conversion, yield and stereochemical course depending on the reaction conditions are discussed.

Pheromone, 1. Mitt.: (+)-cis-Disparlure: Synthese und Feldtests

SummaryA synthesis of (+)-cis-disparlure is described starting from racemic 2-hydroxy-dodecannitrile (2), which is transformed into the O-protected enantiomerically pure cyanohydrine4. Grignardreaction followed by reduction with BH3 · (CH3)2S yields the correspondingthreo-configurated secondary alcohol10. After tosylation and cleavage of theMBE-protective-group (+)-cis-disparlure (14) is obtained by treatment with KOH. Mating disruption field tests exhibited a significantly increased effectiveness of (+)-cis-disparlure as compared to the racemic product.

Synthesis and identification of hydroxylated metabolites of the anti‐estrogenic agent cyclofenil

The detection of metabolites of the anti-estrogenic substance cyclofenil, listed on the World Anti-Doping Agency (WADA) Prohibited List since 2004 is described. Target substances are hydroxylated metabolites, bearing an aliphatic hydroxyl group either in the 2-, 3- or 4-position of the aliphatic ring, in addition to the phenolic functions on the aromatic rings. Structural identification used NMR as well as high-resolution mass spectrometry after nano-electrospray ionisation (ESI). Unambiguous detection of all three synthesised cyclofenil metabolites M1-M3 was done using gas chromatography for separation and electron ionisation mass spectrometry for detection of the per-silylated compounds in comparison with a reference urine deriving from an excretion study within the WADA 2007 Educational Programme.

A facile and high yielding synthesis of 2,2,3,4,4-d5-androsterone-β-d-glucuronide—an internal standard in dope analysis

Abstract A facile six-step synthesis of 2,2,3,4,4-d5-androsterone-β- d -glucuronide (1) starting from epiandrosterone (2) in 63% yield is described and compared with several alternative synthetic pathways. Compound 1 can be used as an internal standard in screening procedures for anabolic steroids to monitor the hydrolysis step of the steroid glucuronides prior to gas chromatography–mass spectrometry (GC–MS) analysis. Thus, a time consuming solid-phase extraction step to remove possible hydrolysis inhibitors can be omitted.

[1,2]-Wittig Rearrangement of Acetals III [1]. New 1,2-Alkoxyalcohols, 1,2-Alkoxyaminesand 1,2-Dialkoxy Compounds as Chiral Ligands for Organomagnesium and Organolithium Compounds and forLithium Aluminum Hydride

Summary. Eight O-substituted 1,2-diols and one O,N-substituted 1,2-aminoalcohol derived from 2-alkoxyoctahydro-7,8,8-trimethyl-4,7-methanobenzofurans via a [1,2]-Witting rearrangement and subsequent substitution were synthesized and tested as additives for the enantioselective addition of butyllithium and butylmagnesium chloride to benzaldehyde and for the reduction of acetophenone with lithium aluminum hydride. The selectivity of the reactions was determined by GC of the obtained 1-phenyl-1-pentanol and 1-phenylethanol on a chiral phase. Best results with regard to selectivity (52% ee and 94% ee, resp.) were achieved in the formation of 1-phenyl-1-pentanol by addition of the substituted 1,2-aminoalcohol to the organometallic reagent and in the reduction of acetophenone using an α-alkoxyalcohol (62%ee).

[1,2]-Wittig rearrangement of acetals. Part 1: Investigation about structural requirements

Abstract Acetals of different alcohols with (+)-camphor derived enantiomerically pure 7,8,8-trimethyl-4,7-methanobenzofuran-2-ol were prepared and subjected to conditions favorable for a [1,2]-Wittig rearrangement. Results with regard to conversion, yield and stereochemical course depending on the structure of the starting material are discussed.

Unambiguous identification and characterization of a long-term human metabolite of dehydrochloromethyltestosterone

In doping control analysis, the characterization of urinary steroid metabolites is of high interest for a targeted and long-term detection of prohibited anabolic androgenic steroids (AAS). In this work, the structure of a long-term metabolite of dehydrochloromethyltestosterone (DHCMT) was elucidated. Altogether, 8 possible metabolites with a 17α-methyl-17β-hydroxymethyl - structures were synthesized and compared to a major DHCMT long-term metabolite detected in reference urine excretion samples. The confirmed structure of the metabolite was 4α-chloro-18-nor-17β-hydroxymethyl-17α-methyl-5α-androst-13-en-3α-ol.