A new strategy for highly concise, convergent, and enantioselective access to polydeoxypropionates has been developed. ZACA‐Pd‐catalyzed vinylation was used to prepare smaller deoxypropionate fragments, and then two key sequential Cu‐catalyzed stereocontrolled sp3–sp3 cross‐coupling reactions allowed convergent assembly of smaller building blocks to build‐up long polydeoxypropionate chains with excellent
Stereochemistry in the hydroboration of allylsilanes
作者:Ian Fleming、Nicholas J Lawrence
DOI:10.1016/s0040-4039(00)87839-9
日期:——
The hydroboration of allylsilanes is highly stereoselective in the sense (3 → 4 and 6 → 7), especially with 9-BBN as the hydroborating reagent. The products can be converted stereospecifically into 1,3-diol derivatives (5 and 8).
The Cu(OTf)2-catalyzed alkyl-alkyl coupling reaction of secondaryalkyl sulfonates with RLi-based reagents prepared by transmetalation with soluble MgBr2 ⋅ THF3 in THF proceeded with inversion of the configuration. RLi examined were nBuLi, sBuLi, and Ph(CH2)4Li. In contrast, soluble MgCl2 ⋅ THF2 in THF was suited for MeLi. (S)-14-Methyloctadecan-2-one, a sex pheromone produced by lichen moths, was