Synthesis of a novel taxa-oxa-sugar hybrid core structure by tandem cross-enyne metathesis/IMDA

摘要

This paper describes our design and efforts in synthesizing new scaffolds with taxol-eleutherobin hybrid core structures and a taxol-sugar hybrid. The synthesis of taxol-eleutherobin hybrids involved the synthesis of the A-ring fragment from carvone and the C-ring fragment from either D-mannose or D-glucose. The Shapiro reaction was used as the key reaction to couple the A- and C-ring fragments of these hybrid structures. Unfortunately, another key reaction (RCM) failed to form the B-ring and essentially the core unit. However, a tandem enyne cross-metathesis/intramolecular Diels-Alder strategy was utilized for the synthesis of a taxa-oxa-sugar hybrid.