Tracer studies of carboxylic acids. 7. Oxygen-18 exchange of propionic acid with solvent water and with surfactant solubilized water in benzene

Abstract

min) showed two major low boilers (89%). By coinjection it was determined that the acetates which result from cleavage of the 2,5 bond (i.e., 9 and 10) comprised <8% of the mixture. The crude acetate mixture was dissolved in 5 mL of ether and treated with 2 mL of methylmagnesium bromide (3 M) at 0 °C for 2 h. The reaction mixture was quenched with 20% NH4C1 and extracted with ether. The crude alcohol mixture thus obtained was directly methylated in 5 mL of THF using 25 m (0.6 mmol) of NaH and 0.4 mL of CH3I. The ether mixture was purified by GLC (6 ft X '/4 in. 20% triscyanoethoxypropane on 60/80 Chromosorb P) and identified as 29b and 30b (1/2.8) by their spectral data and comparison with a sample prepared by a different route.23Acetolysis of the outside,exo-l-OTs was performed at 120 °C for 240 h. Workup and GLC analysis (6 ft X '/s in. 10% Carbowax 20M in 60/80 Chromosorb P, T 151 °C,/30 mL/min) showed a complex mixture of at least four poorly resolved major peaks. The only component which could be isolated from the mixture was identified by comparison with a known sample as the inside, exo-1-OAc. Owing to the complexity of the mixture the reaction was not further investigated.Acetolysis of the outside,exo-2-OTs was performed at 125 °C for 60 h. GLC analysis (10% Carbowax 20M, 145 °C,/ 30 mL/min) showed at least six major products, all poorly resolved. The mixture was not further characterized.Supplementary Material Available: All the spectral data and mass spectroscopic molecular weights (7 pages). Ordering information is given on any current masthead page.