The structures of cyclic aminals from aldehydes and “roofed” mono-<i>N</i>-sulfonyl <i>cis</i>-diamines

Racemic Aldehydes were converted into aminals by using “roofed” mono-<i>N</i>-sulfonyl <i>cis</i>-diamines. Diastereomeric aminals could be separated by silica-gel TLC. The whole configuration of each aminal could be determined by NMR analyses. The chiral reagents were prepared from aminals of racemic reagents and a chiral aldehyde. The reverse may be also true. Epimerization of some aminal remains to be solved. <b>Abbreviations</b>: RDA-Ms: <i>N</i>-(12-amino-9,10-dihydro-9,10-ethanoanthracen-11-yl)-methylsulfonamide; RDA-Ts: <i>N</i>-(12-amino-9,10-dihydro-9,10-ethanoanthracen-11-yl)-4-methylbenzenesulfonamide; RDA-1Nps: <i>N</i>-(12-amino-9,10-dihydro-9,10-ethanoanthracen-11-yl)-1- naphthylsulfonamide; RDA-2Nps: <i>N</i>-(12-amino-9,10-dihydro-9,10-ethanoanthracen-11-yl)-2-naphthylsulfonamide