Open sesame: A directsynthesis of functionalised and stereodefined dienes, relying on a domino allylic alkylation/electrocyclic ring‐opening sequence, is reported. This method allows concise access to doubly vinylogous esters. A further systematic study of ring‐opening rates of carbon‐substituted cyclobutenes allowed the design of substrates amenable to sequential pericyclic reactions (see scheme)
The development of a modular synthesis of 3-substituted-2-pyrones is described The attainment of this strategy hinges on a new electrophilic pyrone derivative which can be readily prepared on a multigram scale and which performs very competently in metal-catalyzed cross-coupling reactions with a variety of nucleophiles