Stereochemistry of Sagittamide A: Prediction and Confirmation
摘要:
The C5-C10 relative stereochemistry of sagittamide A was predicted, with the use of the (3)J(H,H) profiles assembled from the spin-coupling constants reported in the literature. The predicted relative stereochemistry was then confirmed by a total synthesis of two relevant remote diastereomers. The absolute configuration of sagittamide A was established through a detailed H-1 NMR analysis of the two remote diastereomers, followed by doping experiments of them with the authentic natural product.
Stereochemistry of Sagittamide A: Prediction and Confirmation
摘要:
The C5-C10 relative stereochemistry of sagittamide A was predicted, with the use of the (3)J(H,H) profiles assembled from the spin-coupling constants reported in the literature. The predicted relative stereochemistry was then confirmed by a total synthesis of two relevant remote diastereomers. The absolute configuration of sagittamide A was established through a detailed H-1 NMR analysis of the two remote diastereomers, followed by doping experiments of them with the authentic natural product.
Imidazolo-L-lyxo-piperidinose 4 was synthesised from the D-galactose derivative 8 by two reaction sequences via removal of a terminal carbon atom stepwise incorporation of an imidazole moiety, and eventually intramolecular S(N)2 reaction to the corresponding piperidine ring. Piperidinose 4 proved to be a poor glycosidase inhibitor. (C) 1998 Elsevier Science Ltd. All rights reserved.