The absolute configuration of Stachybotrin C was confirmed in this study. After synthesizing the dimethyl ethers of Stachybotrin C, the C-8 epimer was analyzed by 1D NOESY. However, the stereochemistry determination was difficult through the NOE correlations. Instead, the di(4-bromobenzyl) ether of Stachybotrin C was derived and used for X-ray diffraction analysis, because its single crystal was easier to obtain than that of the original Stachybotrin C. The stereochemistry of Stachybotrin C was determined to be (8S, 9R). This derivatization approach may also be used to prepare single crystals of the analogues.

As a new supramolecular tecton based on hydrogen bonding for crystal engineering, benzoic acid derivatives possessing two hydroxymethyl groups were developed and their crystal structures were investigated by single crystal X-ray analysis. The hydrogen-bonded dimer of the acid which possesses four hydrogen-bonding sites creates two types of networks, a zigzag and a straight hydrogen-bonded network. Zigzag hydrogen-bonded networks were created with methoxy (1) and benzyloxy (2) derivatives. It was found that the ladder structure was created via a straight hydrogen-bonded network when 2 included either methanol or ethanol in its cavity. The introduction of a long alkoxy group (hexyloxy) (3) resulted in the formation of an alternate hydrogenbonded network. Ethyl benzoate derivative (4) also formed a hydrogen-bonded network in a zigzag manner.

Two approaches to create hydrogen-bonding (H-bonding) cyclic dimers of tethered benzoic acids in a crystalline state were examined. The cyclic dimers of the methoxy derivative 1 were generated by inclusion of aromatic guest molecules: benzene or benzonitrile. Depending on the size of the guests, the conformation of the pentylene linker of 1 took either the all-trans or 1,2-and 4,5-gauche conformation to adjust the size of the cavity for the guest. The tethered benzoic acids 2 possessing benzyloxy groups as pendants generated a poly(pseudo)rotaxane-like structure in which pendants were included in the cavity of the cyclic dimer itself. In contrast, 1 afforded a zigzag H-bonding network by recrystallization from methanol or ethanol. Incorporation of methanol in the zigzag network was observed when 1 was recrystallized from methanol.

A direct method for preparing bis(alkylamino)maleonitriles from alcohols was developed. Treatment of tertiary alcohols with trimethylsilyl cyanide (TMSCN) and trimethylsilyl triflate (TMSOTf) in the presence of bismuth(III) triflate [Bi(OTf) 3 ] afforded the corresponding bis(alkylamino)maleonitriles in moderate-to-high yields. Tertiary alcohols with various functional groups such as halo, ether, ester, and imide functional groups were tolerated under these conditions. This is the first report of a synthetic method for the preparation of bis(alkylamino)maleonitriles in a single step from tertiary alcohols.