The synthesis of (4S,5S)-(−)-isocytoxazone

(4S,5S)-(−)-Isocytoxazone, which is needed for a configurational study, was synthesized from the commercially available (1S,2S)-(+)-2-amino-1-(4-nitrophenyl)-1,3-propanediol in which the p-nitro substituent was replaced by a p-methoxyl group; the thus prepared p-methoxyphenyl amino diol was cyclized via an N-Boc derivative.

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(1S,2S)-(+)-2-N,N-Dibenzylamino-1-(4-nitrophenyl)-1,3-propanediolC23H24N2O4Ee = 100%[α]D20=+73.5 (c 1.05, MeOH)Source of chirality: stereoselective synthesisAbsolute configuration: (1S,2S)

(1S,2S)-(+)-2-N,N-Dibenzylamino-1-(4-aminophenyl)-1,3-propanediolC23H26N2O2cEe = 100%[α]D20=+94.7 (c 1.03, MeOH)Source of chirality: stereoselective synthesisAbsolute configuration: (1S,2S)

(1S,2S)-(+)-2-N,N-Dibenzylamino-1-(4-iodophenyl)-1,3-propanediolC23H24INO2Ee = 100%[α]D20=+65.1 (c 1.1, MeOH)Source of chirality: stereoselective synthesisAbsolute configuration: (1S,2S)

(1S,2S)-(+)-2-N,N-Dibenzylamino-1-(4-methoxyphenyl)-1,3-propanediolC24H27NO3Ee = 100%[α]D20=+88.9 (c 1.01, MeOH)Source of chirality: stereoselective synthesisAbsolute configuration: (1S,2S)

(1S,2S)-(+)-2-Amino-1-(4-methoxyphenyl)-1,3-propanediolC10H15NO3Ee = 100%[α]D20=+32.5 (c 1.15, 2 M HCl)Source of chirality: stereoselective synthesisAbsolute configuration: (1S,2S)

(1S,2S)-(+)-2-tert-Butoxycarbonylamino-1-(4-methoxyphenyl)-1,3-propanediolC15H23NO5Ee = 100%[α]D20=+27.9 (c 1.0, MeOH)Source of chirality: stereoselective synthesisAbsolute configuration: (1S,2S)

(4S,5S)-(−)-IsocytoxazoneC11H13NO4Ee = 100%[α]D20=-72.5 (c 1.025, acetone)Source of chirality: stereoselective synthesisAbsolute configuration: (4S,5S)