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.     

Caraibical,a new aromatic sesquiterpene from the marine alga laurenciacaraibica

Caraibical, a new aromatic sesquiterpene aldehyde, has been isolated from the marine marine red alga $\text{Laurencia}$$\text{caraibica}$. The structure, which possesses an ether cyclization differing from previous compounds, was defined on the basis of its spectral data.     

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.     

The structure of paraherquamide,a toxic metabolite from penicilliumparaherquei

A new toxic metabolite was isolated from $\text{Penicillium}$$\text{paraherquei}$ and the structure was determined by X-ray diffraction analysis. The metabolite was designated as paraherquamide.     

Structure of spironippol,a new sesquiterpene,from the red alga laurencianipponica yamada

A new sesquiterpene, designated as spironippol, was isolated from the title alga. The structure, which was determined on the basis of the spectral data and X-ray crystallography, represents the biogenetic transition between chamigrane and perforane sesquiterpenes.     

Syncarpurea,a novel metabolite from uvaria afzelii

The isolation and structure determination of syncarpurea (1), a novel urea from $\text{Uvaria afzelii}$ is reported.     

Aflavinine,a novel indole-mevalonate metabolite from tremorgen-producing aspergillusflavus species

The structure of aflavanine, a new diterpene indole from $\text{A}$. $\text{flavus}$, is presented.