Neolignans function

When the alkynyl substrate possesses a nucleophilic functionality, intramolecular solvomercuration reactions can sometimes be observed. These reactions, which result in the formation of a heterocycle, have been used in the total synthesis of natural products. For example, reaction of 114 with Hg(OAc)2 affords the benzofuran derivative 115, which is an important intermediate for the synthesis of various neolignans (Equation (42)).154 155... 

Cationic [5 + 2]cycloaddition involving a styrene and p-benzoquinone ketals in the presence of a Lewis acid is the key reaction to a number of neolignans fe nin [187]. The oxygen atoms of the dioxolane function in the cycloaddend rrinforce the a character of their neighboring carbons, and this character is transmitted to the termini which participate in the C-C bond formations. 

Lewis NG, Davin LB. Evolution of lignan and neolignan biochemical pathways. In Isoprenoids and other natural products Evolution and function. Nes WD, ed. 1994. ACS Symposium Series, Washington, D.C. 

Investigations concerning the function of neolignans in plants would appear profitable in view of the insect antifeeding property of piperenone (7.9a) (J04). 

---