Stereoselective 4-Benzyloxybut-2-enylation of Aldehydes via an Allyl-Transfer Reaction Using a Chiral Allyl Donor
摘要:
A direct and highly stereoselective (E)-4-benzyloxybut-2-enylation of aldehydes was successfully carried out to give 5-benzyloxyhomoallylic alcohol (11) via an allyl-transfer reaction using a chiral allyl donor (10). The chiral allyl donor (10) was prepared by catalytic Sharpless asymmetric epoxidation of 3-methylbut-2-en-l-ol, followed by a stereospecific vinyl Grignard reaction of the epoxide in the presence of CuBr and selective benzylation of the primary alcohol of diol.
Stereoselective 4-Benzyloxybut-2-enylation of Aldehydes via an Allyl-Transfer Reaction Using a Chiral Allyl Donor
摘要:
A direct and highly stereoselective (E)-4-benzyloxybut-2-enylation of aldehydes was successfully carried out to give 5-benzyloxyhomoallylic alcohol (11) via an allyl-transfer reaction using a chiral allyl donor (10). The chiral allyl donor (10) was prepared by catalytic Sharpless asymmetric epoxidation of 3-methylbut-2-en-l-ol, followed by a stereospecific vinyl Grignard reaction of the epoxide in the presence of CuBr and selective benzylation of the primary alcohol of diol.
acid (BBHA) complex-catalyzed asymmetricepoxidation of allylicalcohols is described. The optically active binaphthyl-based ligands BBHA 2a and 2b were synthesized from (S)-1,1′-binaphthyl-2,2′-dicarboxylic acid and N-substituted-O-trimethylsilyl (TMS)-protected hydroxylamines via a one-pot, three-step procedure. The epoxidations of 2,3,3-trisubstituted allylicalcohols using the vanadium complex of