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.
Huang
Li-Fu
LF
Department of Chemistry, National Taiwan University, Taipei 106, Taiwan.
Chen
Chih-Wei
CW
Luh
Tien-Yau
TY