Retrosynthetic Approach Cont OTBS ☆一8 Me OTMS E FG PPh3 C TBSo、:CHo . OH OHOHOH 99: D-mannitol 79: D-mannoseRetrosynthetic Approach Cont. O O O O O O O Me H H H H H H Me H Me H H Me Me Me A OTMS PPh3 87 B C D E F G OH OH OH OH OH OH TBSO CHO Me PivO + 99: D-mannitol 97 O O O H H OTBS EtS H Me I EtS H H O J K OTPS 86 HO O OH OH HO OH 79: D-mannose