β-Substituent Stabilization of Carbanion Intermediates

Abstract

liquor was evaporated to yield a residue which was then washed with dilute sodium hydroxide and recrystallized from 95% ethanol to give 0.17 g. (25%) of the pyrimidone derivative 13b: m.p. 258-259°; X™r6.06 µ;C!Hi0H 265mM(e52,500), 289 (17,100), 300 (16,400), 322 (12,860); n.m.r. r 6.01 (1 proton) and 8.87 (9 protons).

Organic Fluorine Chemistry

“…The following examples are illustrative [403,404]: (232) C F 2-CH 1 KOH, EtOH ... C F 2-C H 1 KOH, EtOH~ CF2-CH [403] I II From the enormous experimental data, especially in the field of cyclic polyfluorohalo-olefins, the following rules can be derived to help estimate the probable results of a reaction [405]:…”

Further reactions of secondary amines and arsines with fluorocycloolefins

“…whereas the across-ring coupling, through four bonds, is greater, being of the order of 10 c.p.s. Park and his co-workers have since found further examples of couplings of this magnitude (13,14), and the For personal use only.…”

“…The chemical shift of the vinylic proton in these cyclobutenes and cyclopentenes seems to be in the range 6-7 p.p.m. (Table 111) (13,14), apart from the amino derivatives. I t is significant that compounds of the type 1 1 ZC=CFCF2CF2 shorn a large upfield shift of the vinylic fluorine resonance xvhen Z is a dialkylamino group (9).…”