Tetrahedron: Asymmetry

First stereoselective synthesis of (4aS, 5R)-4, 4a, 5, 6, 7, 8-hexahydro-4a, 5-dimethyl-2 (3H)-naphthalenone

X Cuesta, A González, J Bonjoch

Index: Cuesta, Xavier; Gonzalez, Asensio; Bonjoch, Josep Tetrahedron Asymmetry, 1999 , vol. 10, # 17 p. 3365 - 3370

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Citation Number: 10

Abstract

The synthesis of enantiomerically pure (4aS, 5R)-hexahydro-4a, 5-dimethyl-2 (3H)- naphthalenone (−)-1 is described for the first time. The synthesis starts from (R)-3- methylcyclohexanone and involves the preparation of Piers enol lactone 6 in its enantiopure form as the key intermediate. Treatment of (+)-6 with methyl lithium followed by an intramolecular aldol reaction gives the bicyclic enone (−)-1.