New asymmetric reactions of 2-formyl- and 2-Acyl-1-[(2,4,6-triisopropylphenyl)sulfinyl]naphthalenes via diastereomeric rotamers

Nucleophilic reactions with Grignard reagents and the Mukaiyama aldol react ions of the naphthaldehydes having the (2,4,6-triisopropylphenyl)sulfinyl. group produced products with high stereoselectivity. In these reactions, th e stereochemistry of the major products changes depending on the Lewis acid s used. Reduction of the 2-acyl-1-[(2,4,6-triisopropylphenyl)sulfinyl]napth alenes also proceeds with high stereoselectivity but with a different stere ochemistry depending on the reducing agents. We have demonstrated, by the m echanistic consideration based on the X-ray crystal structures as well as t he H-1 and C-13 NMR spectral data, that the extremely high and specific ste reoselectivities of these reactions are due to the predominant rotamer arou nd the C-naph-S axis. Synthesis of enantiamerically pure 2-naphthylmethanol is provided as an example.