Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... In the presence of Nidppe, (Z)-1,4-di(2-tetrahydropyranyloxy)-but-2-ene undergoes allylic alkylation with Grignard reagents to give 2-alkylbut-3-enols in satisfactory yields. ... 1-Tetrahydropyranyloxy-2-alkylbut-3-enols arise from (Z)-1,4-di(2-tetrahydropyranyloxy)- ...