Iodinolysis of ethyl 6-O-benzoyl-4-O-methylsulfonyl-2, 3-dideoxy-α-d-erythro-hex-2-enopy- ranoside in the presence of pyridine gives the expected product of inversion, viz. the 4-iodo- 2, 3, 4-trideoxy-α-d-threo congener (8). If, however, the pyridine is omitted, 8 rearranges to give ethyl 6-iodo-4-O-benzoyl-2, 3, 6-trideoxy-α-d-erythro-hex-2-enopyranoside. Reduction of 8 with lithium aluminum deuteride takes three courses: allylic deuterolysis in the ...
