REACTIONS OF SOME ORGANOPHOSPHORUS REAGENTS WITH ACTIVATED CENTERS OF SOME ORGANIC COMPOUNDS

Abstract

Condensation of a-Hydroxy Ketones with Phosphorus Ylides: A Convenient Synthesis of Linear Heterocyclic Formation*

a-Hydroxy ketones la,b reacted with alkoxymethylenetriphenyl­ phosphorane 2a,b in boiling toluene containing benzoic acid. gave the alkencs £-3a-d (48-58%) and the cyclic products 4a,b (-12%). With 2c (R= Me), furoin (Ia) gave the conjugated diene 5 (66%), while benzoin (1b) under the same reaction conditions afforded the diphenylprop-2-cn-1-ol 6 (58%).

y-f"r't-CH( •'""\r Ph3P=CH-COR 0 011 1e,Y,.2-Iureuy( + 2 y a. R= OCH3 1b. =,, b,R= H5 H y 0 OH y OH 4a,b + 2c ! Y H OH E-3a-d Ph Ph !fHCOMe ' I. -CHOH

c.R= CH3

y --.;:: ..-C•Me 1 CH CHCOCH3 6

Treatment of Ia with 2d ( R=H) led to the formation of the oletin 7 (20%) and the dihydrofuran derivative 8a (25%). Applying 2d on I b yielded only 8b (42%).

v, /H Y

>_y=<y

Hb H y 0 OEt

EtO CHCHO EtO CH.CHO 7A 7B 2 7• , Y= 2-furanyl

8a,b a, Y= 2-furanyl b, Y= C 6H5

Phosphorus ylide (Ph3P=CPh 2 ) reacted with dioxolo compounds 9a,b (- 64%).

1a,b, and gave the

v{-}Y

oxo

*This work has been published in:

Ph Ph 9

Heteroatom Chern. 1999, 10 (6), 481.