合成路线1

In a further method, the chiral amino alcohol (IX) was acylated with benzoyl chloride to afford the benzamide (XXVII). Subsequent protection of the hydroxyl group of (XXVII) with dihydropyran provided the tetrahydropyranyl ether (XXVIII). Alternatively, amino alcohol (IX) was initially protected as the tetrahydropyranyl derivative (XXIX), which was subsequently acylated with benzoyl chloride . N-Alkylation of amide (XXVIII) to give (XXX) was either performed with dimethyl sulfate or with methyl iodide in the presence of NaH. Subsequent deprotection of the tetrahydropyranyl ether (XXX) in acidic medium furnished alcohol (XII). This was converted to the sulfonate ester (XXXI) upon treatment with benzenesulfonyl chloride and Et3N. Alternatively, alcohol (XII) was converted to the corresponding mesylate as shown in Scheme 1 (5). Finally, condensation of the benzenesulfonate (XXXI) with piperidine (III) in the presence of K2CO3 in refluxing acetonitrile yielded the title compound