Enantioselective Synthetic Methodology to Prepare trans-Fused Bicyclo[5.3.0]decane Systems: an Approach to the Synthesis of the Pseudoguaiane Carbon Framework

An enantioselective method to prepare trans-fused bicyclo[5.3.0]decane systems is described. This methodology is based on two key reactions: a [4+3] cycloaddition reaction (to generate the seven-membered ring) and the Nicholas reaction (to insert the five-membered ring). The application of this methodology to the enantioselective synthesis of the pseudoguaiane carbon skeleton is presented. This enantioselective strategy for construction of the trans-fused bicyclo[5.3.0]decane system is versatile and could be applied to the preparation of a wide range of bioactive natural products containing that carbon framework.