Enantioselective Synthesis of the Hexahydronaphthalene Nucleus (XIII) of (‐)‐Compactin from Ethyl (1R,2S)‐2‐Methyl‐4‐ oxocyclohexanecarboxylate and 2‐(3‐Nitropropyl)‐1,3‐dioxolane as Four‐ Carbon Bifunctional Annelating Agent.