New preparation procedure for trans-imidodiols of norbornane series

Abstract

Several methods for synthesis of imidodiols of norbornene series were published. In [1, 2] the effect of the character of oxidant used on the stereochemistry of the oxidation process was demonstrated. The goal of this study was a development of a new procedure for preparation of trans-imidodiols Ia–Ie by reaction of exo-2-hydroxy-5-oxo-endo-4-oxatricyclo[4.2.1.03,7]nonane-endo-9-carboxylic acid salts IIa–IIe with dicyclohexylcarbodiimide (DCC). Initial salts salts IIa–IIe were obtained either by epoxidation of amido acids (R = H, CH2Ph) [3] or by reaction of equimolar amounts of exo-2-hydroxy-5-oxoendo-4-oxatricyclo-[4.2.1.03,7]-nonane-endo-9-carboxylic acid with an appropriate amine at room temperature in a dichloromethane solution (salts IIb, IId, and IIe). In the latter case reaction of salts IIb, IId, and IIe with DCC was carried out as a “one-pot” synthesis without isolating salts in individual state. We showed formerly [3, 4] that under similar conditions the dehydration of salts of secondary amines III took an alternative route resulting in corresponding amidolactones IV. N O