CHIRAL TOLUENE-2,α-SULTAM AUXILIARIES: ASYMMETRIC ALKYLATIONS, ACYLATIONS AND ALDOLIZATIONS OF N-ACYL DERIVATIVES

Article abstract of DOI:10.1016/S0040-4039(00)97794-3

Successive treatment of (R)-N-acylsultams 4 with NHDMS/alkyl halides or NHDMS/acyl chlorides provides alkylated or acylated products 6 or 7.Diastereoselective reductions of 7 with Zn(BH4)2 or NaHB(sBu)3 gives "syn"- or "anti"-aldols 8 or 9.Reaction of 4 with BEt3/TfOH/EtN(iPr)2 followed by addition of aromatic or aliphatic aldehydes affords diastereomerically pure "syn"-aldols 10.Non-destructive removal of auxiliary 3 from 6, 8, 9 and 10 yields enantiomerically pure products 12 to 16.