Asymmetric synthesis of (S)-homocitric acid lactone

Starting from (S)-phenylalanine, an asymmetric synthesis of (S)-homocitric acid lactone was achieved using Seebach’s SRS methodology. An intermediate for the synthesis of the (S)-per-homocitric acid lactone has also been synthesized.

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(2S,5S)-5-Benzyl-2-tert-butyl-5-(3-hydroxypropyl)-1,3-dioxolan-4-oneC17H24O4[α]D20=-7.1 (c 1.2, CHCl3)Source of chirality: (S)-phenylalanineAbsolute configuration: (2S,5S)

(2S,5S)-5-Benzyl-2-tert-butyl-5-(carboxyethyl)-1,3-dioxolan-4-oneC17H22O5[α]D20=-10.7 (c 1.1, CHCl3)Source of chirality: (S)-phenylalanineAbsolute configuration: (2S,5S)

(2S,5S)-2-tert-Butyl-5-(carboxyethyl)-5-(carboxymethyl)-1,3-dioxolan-4-oneC12H18O7[α]D20=+16.5 (c 0.77, CHCl3)Source of chirality: (S)-phenylalanineAbsolute configuration: (2S,5S)

Homocitric acid lactoneC14H15NO4[α]D20=+20.2 (c 1.18, MeOH)Source of chirality: (S)-phenylalanineAbsolute configuration: (S)

(2S,5S)-5-Benzyl-2-tert-butyl-5-(3-phenylpropyl)-1,3-dioxolan-4-oneC23H28O3[α]D20=+15.6 (c 0.59, CHCl3)Source of chirality: (S)-phenylalanineAbsolute configuration: (2S,5S)