Syntheses of partially pivaloylated D-glucopyranoses: New substrates for the esterase from rabbit serum

Article abstract of DOI:10.1016/S0008-6215(00)90516-0

The selective pivaloylation (pivaloyl chloride-pyridine) of D-glucopyranose proceeds by two pathways after initial 6-pivaloylation, namely, successive esterification of (a) positions 1, 3, 4, and 2 (major pathway) and (b) positions 2, 1, 4, and 3 (minor pathway). Numerous di- (3 and 4), tri- (5-9), and tetra-pivalates (10-12) have been prepared and characterised. On treatment of the 2,6-dipivalate (4) with rabbit serum or partially purified esterase II, PivO-6 was hydrolysed selectively, whereas the 1,6-dipivalate (3) underwent partial 1 → 2 acyl migration to give 4 and enzymic de-esterification of 3 and 4 occurred simultaneously. The selective pivaloylation (pivaloyl chloride-pyridine) of D-glucopyranose proceeds by two pathways after initial 6-pivaloylation, namely, successive esterification of (a) positions 1, 3, 4, and 2 (major pathway) and (b) positions 2, 1, 4, and 3 (minor pathway). Numerous di- (3 and 4), tri- (5-9), and tetra-pivalates (10-12) have been prepared and characterised. On treatment of the 2,6-dipivalate (4) with rabbit serum or partially purified esterase II, PivO-6 was hydrolysed selectively, whereas the 1,6-dipivalate (3) underwent partial 1→2 acyl migration to give 4 and enzymic de-esterification of 3 and 4 occurred simultaneously.