1993 年 51 巻 7 号 p. 631-640
Significant attentions have been focused on the inclusion chemistry of cyclodextrins and the related compounds and synthetic studies of cyclooligosaccharides have been tarring out intensively. For example, Ogawa and coworkers reported the total synthesis of cyclodextrins and a manno isomer of cyclodextrins by means of phenylselenyl triflate promoted cycloglycosylations. Synthesis of 1-3β linked cycloglucohexaose was reported by Collins' group. Modifications of α-cyclodextrin into trimethyl, 1, 3-anhydro, and a chimera analog have also reported recently. However, cyclooligosaccharide available today is only limited to D series. As we have developed a novel thermal glycosylation procedure, which can be applied to rhamnosylation with high α-selectivity, we designed the synthesis of cyclo-L-rhamnohexaose (40), the first cyclooligosaccharide of L series. On the basis of the area where the compound has been prepared, this compound was named α-cycloawaodorin, which would open a new dimension of the inclusion chemistry.