7a-alkoxy-4H-pyrano [3,2-d] -oxazol-2 (3H) -one and process for producing the same
申请人:——
公开号:US20020072612A1
公开(公告)日:2002-06-13
The present invention provides a novel 7a-alkoxy-4H-pyrano-[3,2-d]-oxazol-2(3H)-one represented by the formula (I):
1
wherein R
1
and R
2
each represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or an aralkyl group; R
3
represents an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group or an aralkyl group, provided that a 2-alkenyl group is excluded from the alkenyl group of R
3
; and R
4
represents an alkyl group, an aryl group, an alkoxycarbonyl group or a cyano group,
and a process for producing the same which comprises reacting 5-alkoxy-2(3H)-oxazolone with an &agr;,&bgr;-unsaturated ketone in the presence of a Lewis acid in a solvent.
本发明提供了一种新型的7a-烷氧基-4H-吡喃-[3,2-d]-噁唑-2(3H)-酮,其化学式表示为(I):其中R1和R2分别代表氢原子、烷基、烯基、芳基或芳基烷基;R3代表烷基、环烷基、烯基、芳基或芳基烷基,但要求R3的烯基中排除2-烯基;R4代表烷基、芳基、烷氧羰基或氰基;以及一种制备该化合物的方法,包括在溶剂存在下,将5-烷氧基-2(3H)-噁唑酮与α,β-不饱和酮在Lewis酸存在下反应。