Abstract In this paper, it is reported that the efficient iodolactonization of 4, 5-allenoic acid with I 2 in cyclohexane in the presence or absence of K 2 CO 3 afforded 5-(1′-iodo-1′(Z)- alkenyl)-4, 5-dihydro-2 (3H)-furanones highly stereoselectively. However, the reaction of axially optically active 4, 5-allenoic acids (R)-(−)-5 a and (R)-(−)-5 b with I 2 afforded the corresponding products with a serious loss of chirality. This problem was solved by ...
