“… , This general strategy involved the preparation of Weinreb amide 19 , which was synthesized in 10 steps from d -glucose (Scheme ). ,, In their synthesis, allyl-protected intermediate 88 was prepared through a four-step process . These steps included condensation of d -glucose with allyl alcohol followed by the protection of the remaining free hydroxy groups using trityl and benzyl chloride and subsequent removal of the O -trityl group in an acidic medium. − Other strategies based on allylation of the polyacetylated d -glucose catalyst with ZnCl 2 followed by protection and deprotection were also employed. , Thus, Swern oxidation of primary alcohol 88 generated the aldehyde precursor, which simultaneously underwent aldol condensation and Canizzaro reduction with formaldehyde to give tetrasubstituted intermediate 89 . , Lactol 92 was then prepared by protection of 89 with p -methoxybenzyl bromide (PMBBr) in the presence of NaH in DMF followed by removal of the allyl moiety by PdCl 2 .…”