General method for the synthesis of [ n .3.3]propellanes, n ≥ 3

Abstract

Reaction of alicyclic-1,2-diones (2a–d) with dimethyl 3-ketoglutarate 1 at room temperature in aqueous buffer (pH = 5.6) provided good yields of the tetramethylpropellanedione tetracarboxylates (3a–d), respectively. Hydrolysis and decarboxylation of the β-ketoester functions, followed by Wolff–Kishner reduction of the corresponding propellanediones (4a–d) has resulted in synthesis of [10.3.3]-, [6.3.3]-, [4.3.3]-, and [3.3.3]propellanes (5a–d). The 13 C nmr of propellanes 5a–c are also reported.[Formula: see text]