Ethylene derivatives synthesis with addition

Aldehydes from ethylene derivatives Synthesis with addition of 1 C-atom... 

Terminal acetylene from ethylene derivs. Stereospecific synthesis with addition of 2 C-atoms... 

This sequence transforms acyclic ketones and aldehydes into a-methylene ketones and a-methyl-a,)5-unsaturated ketones and aldehydes It has been illustrated by the synthesis of eucarvone, ( )-nuciferal and ( )-manicone This ring-opening of chlorosiloxycyc-lopropanes with ClSiMea elimination appears to be a practical route to Z or a,)5-ethylenic aldehydes and ketones depending on the stereochemistry of the reactants. For example, conversion in MeOH-NEta at 20°C of the 2-chloro-2-methyl-3-pentyl-l-trimethylsiloxycyclopropanes (derived from the addition of the chloromethylcarbene to the E and Z silyl enol ethers of n-heptanal) leads either to or Z 2-methyl-oct-2-enal (equation 65). ... 

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