A simple, tandem approach to the construction of pyridine derivatives under metal-free conditions: a one-step synthesis of the monoterpene natural product, (−)-actinidine
followed by concomitant cyclization through an allenylintermediate to afford pyridines in excellent yields, with water as the sole by-product. This mild strategy is also suitable for functionalization of natural products or other advanced intermediates having α,β-unsaturated carbonyl functionality. The utility of the present protocol was showcased with the synthesis of the monoterpene alkaloid, (−)-actinidine