Racemic isobutyl 3,4-anhydro-2,6-dideoxy-β-ribo-hexopyranoside and -lyxo-hexopyranoside have been prepared starting from the cycloadduct between 3-buten-2-one and isobutyl vinyl ether. Alkaline hydrolysis converted the lyxo isomer exclusively into isobutyl 2,6-dideoxy-β-DL-xylo-hexopyranoside (isobutyl β-DL-boivinopyranoside), the ribo isomer into a 57:43 mixture of the same glycoside, and its arabino diastereomer (isobutyl β-DL-olivopyranoside). Rabbit microsomal epoxide hydrolase similarly converted the racemic lyxo epoxide into the xylo diol in a regiospecific way and exhibited a high degree of enantioselectivity: when the enzymatic reaction was stopped at 50% conversion, isobutyl β-L-boivinopyranoside and isobutyl 3,4-anhydro-2,6-dideoxy-β-D-lyxohexopyranoside were obtained, both with an enantiomeric excess of at least 96%.
ALKALINE AND ENZYMATIC-HYDROLYSIS OF ISOBUTYL 3,4-ANHYDRO-2,6-DIDEOXY-DL-HEXOPYRANOSIDES - PREPARATION OF ENANTIOMERIC BOIVINOPYRANOSIDES THROUGH A HIGHLY EFFICIENT KINETIC RESOLUTION
CATELANI, GIORGIO;
1987-01-01
Abstract
Racemic isobutyl 3,4-anhydro-2,6-dideoxy-β-ribo-hexopyranoside and -lyxo-hexopyranoside have been prepared starting from the cycloadduct between 3-buten-2-one and isobutyl vinyl ether. Alkaline hydrolysis converted the lyxo isomer exclusively into isobutyl 2,6-dideoxy-β-DL-xylo-hexopyranoside (isobutyl β-DL-boivinopyranoside), the ribo isomer into a 57:43 mixture of the same glycoside, and its arabino diastereomer (isobutyl β-DL-olivopyranoside). Rabbit microsomal epoxide hydrolase similarly converted the racemic lyxo epoxide into the xylo diol in a regiospecific way and exhibited a high degree of enantioselectivity: when the enzymatic reaction was stopped at 50% conversion, isobutyl β-L-boivinopyranoside and isobutyl 3,4-anhydro-2,6-dideoxy-β-D-lyxohexopyranoside were obtained, both with an enantiomeric excess of at least 96%.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
