Lewis acid mediated control of allylic epoxide opening in carbocyclization and halide addition pathways
作者:Andrew G. Myers、Michael Siu
DOI:10.1016/s0040-4020(02)00653-1
日期:2002.8
cyclizations of an allylic epoxide substrate with a tethered enol(ate) function as nucleophile. Both cation-olefin polycyclization pathways and SN-prime macrocyclization processes were observed to occur in the presence of different Lewis acid additives. Lewis acid additives were also observed to direct the stereochemistry of allylic epoxide opening by SN-prime addition of halide ions. This provided
Enantioselective Synthesis of (−)-Terpestacin and (−)-Fusaproliferin: Clarification of Optical Rotational Measurements and Absolute Configurational Assignments Establishes a Homochiral Structural Series
作者:Andrew G. Myers、Michael Siu、Feng Ren
DOI:10.1021/ja020072l
日期:2002.4.1
An enantioselectivesynthesis of the syncytium formation inhibitor (-)-terpestacin (1, 19 steps, 5.8% yield from the allylation product of (R,R)-pseudoephedrine propionamide, 3) and the fungal metabolite (-)-fusaproliferin (2, 21 steps, 5.3% yield from 3) in their natural configurations is described. The route employs a series of stereoselective enolate alkylation reactions to establish the initial