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.     

Structure of swinholide-a,a new macrolide from the marine sponge theonella swinhoei

Swinholide-A ($\text{1}$a) a novel 22-membered macrolide has been isolated from a Red Sea sponge. The structure of the tetraformate ($\text{1b}$) has been determined on basis of spectral data using 2D-NMR correlations.     

SCH 23831, a novel macrolide from Micromonospora rosaria

A novel macrolid elaborated by $\text{Micromonospora rosaria}$, SCH 23831, was assigned structure $\text{2}$ on the basis of spectroscopic data. Several derivatives are also discussed.     

Engleromycin,a new cytochalasan from Engleromycesgoetzei Hennings

The structure of engleromycin isolated from $\text{Engleromyces}$$\text{goetzei}$ Hennings has been established as $\text{1}$ by spectral techniques.     

Diastereoselective synthesis of N-acetyl-D,L-acosamine and N-benzoyl-D,L-ristosamine

N-Acyl derivatives of $\text{D}$,$\text{L}$-acosamine and $\text{D}$,$\text{L}$-ristosamine were synthesized with high stereo selectivity utilizing intramolecular Michael addition of γ- and δ-carbomoyloxy-α,β-unsaturated esters.     

[2+2] Cycloaddition of benzyne to cis,trans- and cis,cis-1,5-cyclooctadiene

The relative rates of formation of $\text{cis}$ and $\text{trans}$ [2+2]cycloadducts of benzyne to $\text{cis}$, $\text{trans}$- and $\text{cis}$, $\text{cis}$-1,5-cyclooctadiene, $\text{trans}$- and $\text{cis}$-cyclooctene are discussed and properties of the adducts (e.g., their unusual hydrogenation) are described.     

Structure of koumine,an alkaloid from gelsemiumelegans benth

The structure of koumine, an indole alkaloid from $\text{Gelsemium}$$\text{elegans}$ Benth., was determined by a X-ray crystallographic study.