The coupling of 1,3-dienyl alcohols with boryl-3-propenoic acid 1 or of 1,3-dienyl secondary amines with the acid chloride 2 leads to the trienes 5 and 6 respectively. These are well suited precursors for an intramolecular Diels-Alder reaction leading to bicyclic cycloadducts having a carbon-boron bond which can be stereoselectively transformed into a CO or CC bond. Thus, the cycloadduct 9 gave the