SYNTHESIS OF 2'-(3-ALPHA-BENZYLOXY-24-NORCHOLAN-23-YL)-2',4',4'-TRIMETHYL-4',5'-DIHYDROOXAZOLINE-N-OXYL - A NEW POTENTIAL SPIN PROBE FOR BIOMEMBRANES

Abstract

The synthesis of a new steroidal nitroxide, viz. 2'-(3-alpha-benzyloxy-24-norcholan-23-yl)-2',4',4'-trimethyl-4',5'-dihydrooxazoline-N-oxyl 7, a potential spin probe for biomembranes is described. The title compound in improved yield could be obtained by a direct Grignard reaction on the oxaziridine 4. This effected a one-step reduction in the overall synthetic sequence. The methodology of the Grignard reaction on the oxaziridine to yield the nitroxide is reported for the first time. In dilute solutions, the isotropic ESR parameters for 7 have been measured.