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.     

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.     

Reappraisal of the structure for the alkaloid buddamin from buddleyadavidii

The structure of the alkaloid buddamin, isolated from $\text{Buddleya}$$\text{davidii}$ cannot be correct, based upon the reported spectral data. An alternate structure is proposed, which also suggests that buddamin is an artifact of the isolation procedure.     

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.     

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.