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1,1-Dimethyl-5,6-dihydroxyindolinium chloride (1a)was identified from a deep water sample of the marine sponge,Dercitus sp., and its structure was elucidated by spectral methods.

Asymmetric Diels–Alder reaction of the chiral acrylamide 1 proceeds highly diastereoselectively and methanolysis of the adduct 2 gives the optically pure (3R, 4R, 6R)-bicyclo [2. 2. 1]heptene-4-carboxylate.

The oxidative substitution reaction of olefinic tin compounds with lead tetraacetate(LTA) was investigated. The oxidation is highly regioselective and gave a dipole inversed product (acetate) in good yield.

A first transition state model for the rearrangement of acylisoureas is proposed from the stereoselectivity of the reaction with chiral acylisoureas.

An alteration of the regioselectivity in dianion formation, from the usual α,α-dianions to the uncommon α,β-dianions, of nitroethane and 1-nitropropane was established by changing the order of addition of reagents.

A highly stereo- and regio-selective radical cyclisation of homoallylic xanthate esters is presented and the reaction is applied to the synthesis of some ring fused lactones.

Methylene Blue sensitized photo-oxidation of dimethyl oxosulphonium and pyridinium bis(methoxycarbonyl)methylides in chloroform gave dimethyl sulphoxide and pyridine as the main products respectively, together with dimethyl mesoxalate; the photo-oxidation of diphenyl sulphide afforded diphenyl sulphoxide, and the results indicate that an oxygen atom is transferred to diphenyl sulphide from oxenoid rather than from 1,2-dioxetan intermediates.

The first example of a formal homo-Cope rearrangement in azoalkane chemistry is presented; a double bond in the proximity of a denitrogenation site participates in the rearrangement.

Photosensitized oxygenation of fluorenylidene derivatives in methanol gives 1-hydroxyfluoren-9-one and 1-hydroxy-9-methoxy-9-(1-hydroxy-1-methylethyl)fluorene which appear to arise via either 1,4-cycloaddition or a peroxiran intermediate; the reaction is influenced by the nature of the substituents on the exocyclic carbon atom.

Trimethylsilyl trifluoromethanesulphonate is found to be an efficient catalyst for the reaction of 1,4-endoperoxides and 1,2-dioxetanes with aldehydes and ketones to give 1,2,4-trioxanes in high yields.

1,2,4-Trioxanes bearing a hydrogen substituent at the C-3 position when treated with trithylamine undergo scission of the oxygen-oxygen bond to give the corresponding 1,2-diol monoesters in high yields; similar treatment of a bridged 1,2,4-trioxane afforded the related γ-hydroxy-δ-lactone and its isomeric spirocyclic δ-lactone in 90% yield.

The acid-catalysed cleavage of 1,4-dimethyl-1,4-dihydronaphthalene-1,4-endoperoxide gives the 4-hydroxy, methoxy, trifluoroacetoxy, formyloxy, bromo, and chloro methyl derivatives of 1-methylnaphthalene in yields of 36,38,52,76,77, and 100% respectively when water, methanol, trifluoracetic, formic, hydrobromic, or hydrochloric acids are used as reagents.

Photo-oxygenation of vinyl sulphides sensitized either by dyes or by 9,10-dicyanoanthracene (DCA) gave products arising from oxidative cleavage of the double bond in closely similar ratios in each case; similarly, dye-photosensitized oxygenation of fluorenyl ethyl sulphide gave fluorenone, 1-hydroxy-9-fluorenone, 9-fluorenyl ethyl sulphoxide, and 9-fluorenyl ethyl sulphone as major products, while DCA-sensitized oxygenation gave the first three products in similar relative yields.