ChemInform Abstract: An Investigation of the Diastereoselectivity of Nucleophilic Additions to 6-Methyl-1-oxa-4-thiaspiro[4,5]dec-6-ene-7-carbaldehyde. Hybridization of the Nucleophile Alters the Diastereoselectivity.

✍ Scribed by D. A. JEYARAJ; V. K. YADAV; M. PARVEZ; H. M. GAUNIYAL

• Publisher: John Wiley and Sons
• Year: 2010
• Weight: 40 KB
• Volume: 29
• Category: Article
• ISSN: 0931-7597
• DOI: 10.1002/chin.199845048

✦ Synopsis

An Investigation of the Diastereoselectivity of Nucleophilic Additions to 6-Methyl-1-oxa-4-thiaspiro[4,5]dec-6-ene-7-carbaldehyde. Hybridization of the Nucleophile Alters the Diastereoselectivity. -A change of the nucleophile hybridization from sp 3 to sp 2 and sp changes the diastereoselectivity of the title reaction. sp 3 Nucleophiles show marginal favor of attack anti to sulfur, while sp 2 and sp nucleophiles exhibit improved but reversed π-selection. The reason for this reversal is believed to be an electrostatic attraction between the electron-deficient sulfur atom and the sp 2 and sp nucleophiles having the negative charge largely concentrated at the carbon atom. The diastereoselectivity observed is neither steric in nature nor does it obey the dipole model proposed by Wipf and Kim. -(JEYARAJ, D.