Synthesis of Heteroanellated Pyranosides Starting from Methyl 4,6‐<i>O</i>‐benzylidene‐2,3‐dideoxy‐α‐<scp>d</scp>‐<i>erythro</i>‐hexopyranosid‐2‐ylidenemalononitrile
作者:Holger Schulz、Holger Feist、Klaus Peseke
DOI:10.1080/07328300500495852
日期:2006.1.1
The hexopyranosid-2-ylidenemalononitrile 1 reacted with phenyl isothiocyanate in the presence of triethylamine to furnish (2R ,4aR ,6S ,10bS )-8-amino-4a,6,10,10b-tetrahydro-6-methoxy-2-phenyl-10-phenylimino-4 H-thiopyrano[3',4':4,5]pyrano[3,2-d][1,3]dioxine-7-carbonitrile (2). Starting from 1, cyclization with sulphur and diethylamine yielded (2R ,4aR ,6S ,9bR )-8-amino-4,4a,6,9b-tetrahydro-6-methoxy-2-phenylthieno[2',3':4,5]pyrano[3,2- d][1,3]dioxine-7-carbonitrile (3), which could be transformed into the corresponding aminomethylenamino derivative 4 by treatment with triethyl orthoformate and ammonia. Intramolecular cyclization of 4 to yield (2R ,4aR ,6S ,11b R )-4,4a,6,11b-tetrahydro-6-methoxy-2-phenyl[1,3]dioxino[4?,5?:5',6']pyrano[3',4':4,5]thieno [2,3- d ]pyrimidin-7-amine (5) was achieved by using NaH as base. (2R ,4aR ,6S ,9bS)-8-Amino-4a,6,9,9b-tetrahydro-6-methoxy-9-(4-methylphenyl-sulfonyl)-2-phenyl-4 H -[1,3]dioxino[4',5':5,6]pyrano[4,3- b]pyrrole-7-carbonitrile (6) was prepared by treatment of compound 1 with tosylazide and triethylamine.