1,2-Enedioic systems, being sterically perturbed from planarity do not show the effect of the extended conjugation expected of a (formal) trienic entity. In the absence of a model which approximates to a uniplanar situation, the strategy of replacing an ester group in the enedioates by a cyano (for which less stringent steric demand may be presumed) and noting the correction concomitant to this replacement was adopted to arrive at a notional figure for the position of maximal absorption in the planar enedioates. From this the conclusion, subject to substantiation by molecular mechanical or quantum chemical calculations, was drawn that even the E-isomeric and comparatively less substituted enedioates are highly sterically perturbed. An alternative to an earlier explanation of the bathochromic shift of absorption maxima encountered in the 5-cyclic ene-ester and ene-nitrile, relative to the 6-cyclic analogues (observed also with the enedioates and cyanovinyl ester systems), seen later to have been based on unwarranted premises, has been advanced. A comment on the absorption characteristics of enedioic anhydrides has been appended.

cis- andtrans-4,6-Diaryltetrahydropyran-2-ones were synthesised from the corresponding ketoesters. High resolution NMR spectral data reveal that they are stabilised in half-chair conformations.

Allyl and benzyl ethers of alcohols can be prepared conveniently and in high yield with allyl and benzyl bromide in the presence of solid potassium hydroxide without use of any solvent. Phenols can be converted to allyl ethers but are inert to benzylation under above conditions.

Copper(I) iodide efficiently catalyzes deformylative C-N coupling of formamides and isoindolinone3-ols to provide C(3) primary/secondary amine substituted isoindolinones. The transformation requires a stoichiometric amount of phenylboronic acid as a co-reactant. In the reaction, formamides act as the synthetic equivalent of primary/secondary amines. The method is amenable for the synthesis of a combinatorial library of medicinally relevant C(3) amino substituted isoindolinones.