Au-Catalyzed Synthesis of (1<i>Z</i>,3<i>E</i>)-2-Pivaloxy-1,3-Dienes from Propargylic Pivalates
作者:Guotao Li、Guozhu Zhang、Liming Zhang
DOI:10.1021/ja800001h
日期:2008.3.1
Propargylic pivalates with electronically unbiased internal alkynes are selectively transformed into (1Z,3E)-2-pivaloxy-1,3-dienes containing various functionalities. The unusual selectivity of 1,2-acyloxy migration over the structurally preferred 3,3-rearrangement is realized. This reaction is highly stereoselective and offers rapid access to dienes for one-pot intra-/intermolecular Diels-Alder reactions either under thermal conditions or with Lewis acid catalysis.
Stereoselective Dichlorination of Allylic Alcohol Derivatives to Access Key Stereochemical Arrays of the Chlorosulfolipids
作者:Grant M. Shibuya、Jacob S. Kanady、Christopher D. Vanderwal
DOI:10.1021/ja804167v
日期:2008.9.17
Dichlorination of (Z)-allylic trichloroacetates efficiently and stereoselectively generates the syn,syn hydroxydichloride stereotriad that is prevalent in the understudied polychlorinated sulfolipid class of natural products. Further, the dichlorination of a (Z)-allylic chlorohydrin affords with high selectivity a stereotetrad present in one of the chlorosulfolipids.