(S)-2-(1-pyrrolidinylmethyl)pyrrolidine center dot HCl crystal structure and use in the chiral lithium amide base mediated rearrangement of cyclohexene oxide

X-ray crystallographic characterization of (S)-2-(1-pyrrolidinylmethyl)pyrr olidine . HCl 3, obtained from the chiral diamine (S)-2-(1-pyrrolidinylmeth yl)pyrrolidine 1, is described. Furthermore, the efficiency of lithium (S)- 2-(1-pyrrolidinylmethyl)pyrrolidide 2, (made by reaction of n-butyllithium (n-BuLi) with (a) 1, (b) 3) and crystallized 2, in the enantioselective rea rrangement of cyclohexene oxide to (S)-2-cyclohexen-1-ol 4 is compared. Wit h the use of crystalline 3 and n-BuLi (2 equiv.), 4 was obtained in 74% ena ntiomeric excess (ee).