Synthesis Of S-Linked Trehalose

A facile and highly stereoselective synthesis of1-thiotrehalose, i.e. a,a-S-linked trehalose, is described. Glycosylation of configurationally pure a-glucosyl thiol with glucosyl trichloroacetimidate or glucosyl thioimidate followed by deprotection afforded1-thiotrehalose in excellent a-stereoselectivity and high yield. A different synthetic route to the key building block, a-glucosyl thiol was also trialled in this report.The thesis starts with an introduction to trehalose covering its biological importance and utility. Synthesis of trehalose and its analogues was also reviewed in this section.Subesquently, retrosynthetic analysis of thiotrehalose was undertaken. Synthesis of the1-thiotrehalose requires the construction of the challenging a,a-S-(1,1’)-linkage. In practice, we first prepared configurationally pure a-glucosyl thiol by a procedure developed in our laboratory.Next, glycosylation of the a-glucosyl thiol with either Schmidt donor or thioimidate donor led to the desired1-thiotrehalose in excellent a-stereoselectivity and very high yield.