Halichondrin B: Synthesis of the C(1)−C(15) Subunit
作者:Steven D. Burke、Kyung Woon Jung、William T. Lambert、Jeannie R. Phillips、Jason J. Klovning
DOI:10.1021/jo000140r
日期:2000.6.1
A short and efficient synthesis of the C(1)-C(15) subunit of halichondrin B in its natural configuration is described. The polycyclic caged ketal 3, containing nine asymmetric centers, is prepared in 14 steps from alpha-D-glucoheptonic acid gamma-lactone (7). Key steps in the two similar routes described include EtMgBr-promoted pinacol ring expansions of hydroxy mesylates 23 and 34, intramolecular