Iron-promoted elimination of beta-thioalkoxy alcohols. Olefination by coupling of a carbonyl group with a dithioacetal.
Treatment of propargylic dithiolanes with nBuLi followed by a carbonyl electrophile yields the corresponding propargylic dithioacetals. Upon treatment with 1 equiv of Fe(acac)3 and excess MeMgI, elimination of SR and OH moieties from 8 affords the corresponding olefins in satisfactory yield. Benzylic dithioacetals behave similarly. The reaction can be considered an alternative of McMurry coupling of two different carbonyl equivalents.
Department of Chemistry, National Taiwan University, Taipei 106, Taiwan.
Li-Fu
LF
Huang
Chih-Wei
CW
Chen
Tien-Yau
TY
Luh