5 X= COzCH, 8a X= H, Y= OH 6 X= CHzOH 8b X= OH, Y= H 7 X= CHO 9 X, Y= o triethylamine, as two anomers in a 4: l ratio; TLC R,-values 0.42 and 0.40, respectively, with use of 1 2 1 hexane-ethyl acetate). Reduction of 5 using lithium aluminum hydride in ether at 0" C for 1 h gave diol 6 which upon Swern oxidation in methylene chloride with 3 equiv of oxalyl chloride and 6 equiv of dimethyl sulfoxide at-45" C followed by 8 equiv of ...
