The reaction of 2-thioxo-4-thiazolidinone (1a) with phosphorus ylides 2a an
d 2b afforded compounds 5 and 6. On the other hand, formylmethyl-enetriphen
ylphosphorane (2c) reacts with la and its N-methyl derivative Ib to give th
e new complicated phosphoniurn ylides 7a,b, respectively. Reactions of Ib w
ith ylides 2a and 2d gave rise to the olefinic compound 8 and the Mew phosp
horane product 9. Moreover, dialkyl phosphites 3a,b and trialkyl phosphites
4 a-e react with la to give both the alkylated products 10a-c and the dime
ric compounds 11,12. A mechanism is proposed to explain the formation of th
e new products. (C) 1999 John Wiley & Sons, Inc.