E-4-β-D-Allopyranoside–cinnamic-4-substituted phenyl ketone(3a-3h) which contains the structure of chalcone is synthesized by Schmidt-Claisen reaction with helicid and 4-sbstituted hypnone, by this way three new compounds : 3c、3e、3f are obtained. The chalcone is then reacted with malononitrile by Michael addition ,and followed by cyclization 、Dimroth rearrangement、oxidation , thus leads to the pyridine derivatives(10a-10h )of helicid. Catalytic reduction of 10e with hydrazine leads to 10i. A total of 12 unreported new compounds are obtained, the structure is confirmed by 1H NMR, IR and HRMS spectroscopy. The preliminary bioassay tests of 10a-10i show that some of the compounds have a better sedative and hypnotic activity. The major side reaction of Schimdt-Claisen condensation is analyzed. And the mechanism of oxydehydrogenation that leads to the formation of pyridine derivatives by the reaction of chalcone with malononitrile and sodium methoxide is firstly revealed.

Key words: helicid, Schmidt-Claisen reaction, oxydehydrogenation, reaction mechanism, pyridine