Bimanes. 15. Kinetics and Mechanism of the Hydroxide Ion Reaction with 1,5-Diazabicyclooctadienediones (9,10-Dioxabimanes)

Article abstract of DOI:10.1021/jo00143a009

The rate constants for the reaction of hydroxide ion with syn- and anti-9,10-dioxabimanes (1,5-diazabicyclo<3.3.0>octadienediones) correlate with the function , ρ value of 3.0 (R2 = CH3 or H), and with , ρ value of ca. 4 (R1 = Cl or H).The ρ value for hydrolysis of lactones produced by photoisomerization of anti-bimanes is 3.7.Structures of the ring-opened hydrolysis products as 1(2)-pyrazolinonylacrylic acids have been confirmed for both syn- (2-acid) and anti-bimanes (1-acid).The E configuration is established by 1H NMR for the side chain of the hydrolysis product of syn-(H,H)B.Identical ring-opened acids are obtained from anti-bimanes and the lactones.The ring-opened acids are cyclized readily to the anti-bimanes and/or lactones; some data on the facility of the conversion are presented.The present study provides information valuable for improving the yields of bimanes and the design of biological labeling experiments.