3S,4R,5S)-20 in 28% yield and 3,4-cis-δ-lactone ( )-(3R,4R,5S)-21 in 45% yield. Dibal-H reduction of ( )-(3S,4R,5S)-20 followed by catalytic hydrogenation gave L-oleandrose (6) in 86% overall yield, while Dibal-H reduction of ( )-(3R,4R,5S)-21 followed by catalytic hydrogenation provided Lcymarose (7) in 85% overall yield.