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The reaction of acetanilide (1) with nitrobenzene (2) in the presence of a base in DMSO yielded p -nitrosodiphenylamine (3) as the major product. This unusual regioselective formation of the deoxygenated product 3 has been rationalized in terms of solvent effects exerted by DMSO.

Photolysis of the enones 4a–c leads to regioselective hydrogen abstraction and subsequent cyclization to furnish the spiro compounds 5a–d, which on further elaboration provide the spiro dione 6, a model for the antitumour antibiotic, fredericamycin-A 1.

Synthesis of (±)heritol and epi -heritol is described. The key step is the osmylation of the unsaturated ester 9a. Osmylation is used as a tool to construct the α,β-unsaturated γ-lactone system.

Osmylation of β,γ-unsaturated esters and acid catalysed cyclisation of the resultant diols generate butenolides in high yields.

A novel synthesis of unsymmetrical azo aromatics inaccessible by diazo-coupling reaction is reported. The synthesis involved the reaction of acetanilides with nitroarenes under moderate reaction conditions. A reaction pathway via a nitrosoarene intermediate involving elimination of the elements of the acetate anion, is proposed.

An efficient, one pot strategy for the synthesis of spiro [4. n]dione and 2,2-disubstituted cyclopentane-1,3-dione has been developed by using ketals and 1,2-disilyloxycyclobutene in the presence of excess BF 3.Et2O.

Acylation, benzoylation, toluylation and related reactions of active methylenes, e.g. indene, fluorene and diethylmalonic ester is enhanced by the use of solid-liquid phase transfer catalyst. An interesting rearrangement with phthaloyl chloride is reported under identical conditions.

Marschalk reaction of leucoquinizarin (2) with readily obtainable 4-bromo-2-acetoketal-1-butyraldehyde (3), from ethyl acetoacetate or acetone, gave in one step 4-demethoxy-7, 9-dideoxydaunomycinone (1a) in 60% yield.

A novel route to the model spiro-compound 4, for Fredericamycin A (1) is reported, which involves the use of PTC for activating indenyl anion nucleophilicity. A parallel photo-route to 4, from 9 and (or) 10 is described.