Synthesis of phospholane 1-oxide having oxygen functional groups from a 4-bromobutylphoshinate derivative

Ethyl 4-bromo-2,3-dimethoxybutyl(phenyl)phosphinate (10a) was prepared from 2,3-di-0-methyl-L-threitol (12) in five steps. Reduction of 10a with sodium dihydrobis(2-methoxyethoxy)aluminate, followed by the action of hydrogen peroxide, afforded 3,4-dimethoxy-1-phenylphospholane I-oxide (3), while the reaction of 10a with magnesium in boiling THF resulted in the formation of ethyl 2-methoxy-3-butenyl(phenyl)phosphinate (26).