A method for the systematic resolution of unbranched α-acetoxyalkyl- and aralkylaldehydes: synthesis of 11R and 11S-hete

It is shown that oxazolidines derived from racemic unbranched α-acetoxyaldehydes and ?-ephedrine have predictable chromatographic mobilities, with the R-isomer always having a higher R_f-value. This resolution has been used to prepare $\text{11R}$ and $\text{11S}$-HETE.     

Stereoselective synthesis of (1R,3R,5S-1,3-dimethyl-2,9-dioxabicyclo[3.3.1]nonane

(1$\text{R}$,3$\text{R}$,5$\text{S}$)-1,3-Dimethyl]-2,9-dioxabicyclo[3.3.1]nonane $\text{1}$ has been stereoselectively synthesized based on a highly stereoselective method for the synthesis of 1,3-$\text{syn}$-polyol.     

Aymmetric synthesis of (R) - and (S)-citramalate in high enantiomeric purity

An asymmetric synthesis of both isomers of dimethyl 2-acetoxycitramalate in over 96% enantiomeric excess is described.     

Stereocontrolled (E,Z and erythro, threo) synthesis of ⊙-hydroxyallylic sulphides

All four isomers of substituted 3-alkylthio-4-hydroxybutenes have been synthesised: both the geometry of the double bond and the relative stereochemistry of the two chiral centres are controlled.     

A short synthesis of (s)-5-hydroxymethyl-(5h)-furan-2-one and derivatives from d-ribonolactone

We describe a short synthesis of ($\text{S}$)-5-hydroxymethyl-(5$\text{H}$-furan-2-one and some 5-O-derivatives, which are being used as key starting products for the synthesis of several antileukaemic lignan lactones, from $\text{D}$-ribonolactone.     

R - phenyl bis diphenylphosphinoethane; structural studies pertaining to rhodium - catalysed asymmetric hydrogenation

Intermediates in asymmetric hydrogenation by the title phosphine are defined by NMR techniques.     

Synthesis of the enantiomeric forms of cis and trans 1-benzyloxy-2,3-epoxy butane and of (3S,4S) 4-methyl-3-heptanol

The C₄erythro and threo diols (7) and (8) are converted either into the chiral epoxides (13) and (15) or into the enantiomers (14) and (16); the epoxide (13) is used as chiral synthon for the preparation of (3$\text{S}$,4$\text{S}$) 4-methyl-3-heptanol (21).     

Enantiocontrolled synthesis of (S)-3-substituted cycloalkanones from (s)-2-(p-tolylsulfinyl)-2-cycloalkenones and diorganomagnesium reagents.

By appropriate choice of reaction conditions, the $\text{same}$ enantiomerically pure ($\text{S}$)-(+)-2-($\text{p}$-tolylsulfinyl)cycloalkenone can be converted into $\text{either}$ an ($\text{R}$)-or an ($\text{S}$)-3-substituted cycloalkanone in good to excellent enantiomeric purity.     

Highly stereoselective asymmetric synthesis of (R)-(−)-mevalolactone

An asymmetric synthesis of ($\text{R}$)-(?)-mevalolactone in over 87% enantiomeric purity is described.     

Autorecycling oxidation of alcohol catalyzed by 1,3,7,9,11,12,14-heptazapentacene-2,4,8,10 (14H,3H,9H,12H)-tetraones (mixed flavins)

1,3,7,9,11,12,14-Heptazapentacene-2,4,8,10 (14$\text{H}$,3$\text{H}$,9$\text{H}$,12$\text{H}$)-tetraones (mixed flavins) were prepared by the cyclization of 1,5-dihydro-8-[N-alkyl-N-(5-nitrouracil-6-yl)-amino-5-deazaflavins with Vilsmeier reagent. The mixed flavins oxidized alcohol under neutral condition in sunlight and a remarkable autorecycling was observed.     

(10R̃, 11R̃)-(+)-squalene-10, 11-epoxide: Isolation from Laurencia okamurai and the asymmetric synthesis

From a red alga $\text{Laurencia okamurai}$ (10$\text{R}\text{?}$, 11$\text{R}\text{?}$)-(+)-squalene-10, 11-epoxide $\text{1}\text{?}$ was isolated and its asymmetric synthesis has been achieved starting from $\text{trans, trans}$-farnesol.     

Stereospecific total synthesis of 12-(r)- and 12- (s)-forms of 6-trans leukotriene B

Non enzymatic hydration of leukotriene A ($\text{1}$), the biogenetic precursor of leukotriene B ($\text{2}$) affords among other products two diastereomeric 6-$\text{trans}$-isomers of 2, the first stereospecific and efficient syntheses of which are recorded herein.     

MIRC (Michael Initiated Ring Closure) Reactions Formation of Three,Five, Six and Seven Membered Rings

The term MIRC reaction is defined. Examples of the construction of three, five, six and seven membered rings using alkylthiolates and LDA as nucleophiles are presented.