p-tolyl sulfoxides, prepared from ketones and chloromethyl p-tolyl sulfoxide, with N-lithio arylamines resulted in the formation of sulfinylaziridines in good to high yields. The sulfinylaziridines were treated with N-lithio aniline or N-lithio p-chloroaniline to afford α-quaternary α-amino aldehydes in good yields. From α-quaternary α-amino aldehydes, α-quaternary α-amino acid esters and β-quaternary β-amino
An asymmetric synthesis of esters and γ-lactones with simultaneous construction of vicinal stereogenic carbons at the α- and β-position starting from optically active 1-chlorovinyl p-tolyl sulfoxides
Treatment of optically active 1-chlorovinyl p-tolyl sulfoxides with two different substituents at the 2-position, which were synthesized from aldehydes or unsymmetrical ketones and (R)-(-)-chloromethyl p-tolyl sulfoxide in two or three steps, with the lithium enolate of carboxylic acid tert-butyl esters gave the adducts with substituents at the alpha- and beta-position with high 1,3- and 1,4-chiral induction from the stereogenic sulfur center in high yields. The adducts were converted to optically active esters and gamma-lactones having stereogenic centers at the alpha- and beta-position in good to high yields. This procedure offers a new method for a synthesis of optically active carboxylic acid derivatives with stereogenic centers at the alpha- and beta-position. (C) 2008 Elsevier Ltd. All rights reserved.