Phenyl sulfoxide, isopropyl structure

Methyl m-tolyl (8), ethyl m-tolyl, methyl n-butyl and methyl n-propyl sulfoxides were obtained in 100% e.e. This method was less successful when applied to methyl phenyl sulfoxide (5% e.e.) or to methyl isobutyl and methyl ethyl sulfoxides (25% e.e.). No complexes were formed between methyl o-tolyl, methyl p-tolyl, methyl 2-butyl and methyl isopropyl sulfoxides so these compounds could not be resolved using 7. A crystal structure of the 1 1 complex formed between 7 and 8 revealed that the partners were linked by OH—OS hydrogen bonds in endless zig-zag chains23. More recently, 2-chloroethyl m-tolyl sulfoxide (9) has been resolved using 724. 

Figure 3 Inclusion compound of (S )-isopropyl phenyl sulfoxide by 1 (a) perspective view of crystals (b) sheet structure of 1 (c) CPK model. For clarity, phenyl groups of 1 and guest are unshaded and gray, respectively.

The inclusion compounds of 1 and 2 were obtained by crystallization from an appropriate solvent system containing a guest (vide infra). (R) -1 hen y I <21 y cy I - (A1) - pheny lg I y cine (1) molecules self-assemble to form a layer structure and (.V)-isopropyl phenyl sulfoxide molecules are stereospecifically included in the void between the layers (Figure 4)7 A sheet structure was also observed in THF-included crystals of (/ )-(l-naphthyl)glycyl-(/ )-phenylglycine (2), which were formed by crystallization of 2 from a mixed solvent of tetrahydrofuran (THF) and... 

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