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 α- and β-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 γ-lactones having stereogenic centers at the α- and β-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 α- and β-position.

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(2S,3R,4S,SR)-tert-Butyl 3-[chloro(p-tolylsulfinyl)methyl]-2,3-dimethyl-5-phenylpentanoateC25H33O3ClS[α]D27=-50.9 (c 1.77, EtOH)Source of chirality: (R)-(−)-chloromethyl p-tolyl sulfoxideAbsolute configuration: (2S,3R,4S,SR)

(3R,4R)-3,4-Dimethyl-4-(2-phenylethyl)tetrahydrofuran-2-oneC14H18O2De = 98%, ee = 98%[α]D26=-11.0 (c 0.93, EtOH)Source of chirality: (R)-(−)-chloromethyl p-tolyl sulfoxideAbsolute configuration: (3R,4R)