The reaction of crotyltrialkylstannanes (1) with aldehydes in the presence of BF3,OEt2, produces the corresponding erythro homoallyl alcohols (2) predominantly regardless of the geometry of the double bond. Further, the Lewis acid mediated reaction exhibits the enhanced Cram selectivity in comparison with other allylic organometallic reactions which proceed in the absence of Lewis acids. Use of AlCl3-i-PrOH
Highly diastereoselective reactions using masked allylic zinc reagents
作者:Philip Jones、Paul Knochel
DOI:10.1039/a805953e
日期:——
Substituted allylic organozinc reagents have been prepared using a novel fragmentation reaction; the resulting allylic zinc species are configurationally stable and give excellent regio- and diastereo-selectivities.
Erythro-selective addition of crotyltrialkyltins to aldehydes regardless of the geometry of the crotyl unit. Stereoselection independent of the stereochemistry of precursors