Alkynoates as a source of reactive alkylinides for aldehyde addition reactions.

[see reaction]. The reaction of activated alkynes with carbonyl compounds in the presence of a catalytic amount of a nucleophile leads to enol-protected functionalized propargyl alcohols and 1,3-dioxolane compounds by way of a mild carbon-carbon bond formation reaction.

Highly 2,3-trans stereoselective allylations of 2, 3-O-isopropylidene-protected pyrrolidines: circumventing the N-acyliminium ion chemistry?

[reaction: see text] A remarkable exo-facial template effect exercised by a 2, 3-O-isopropylidene protective group is the key for the entire 2, 3-trans stereoselectivity observed in the allylsilane addition promoted by BF(3).OEt(2) to 2,3-O-isopropylidene-protected pyrrolidines.