Diterpenoid and phenolic glycosides from the roots of Rhododendron molle.

Two new grayanane diterpenoid glucosides, rhodomosides A (1), B (2) and two new phenolic glycosides 3, 4 together with a known glucosyringic acid (5) were isolated from the roots of Rhododendron molle G. Don (Ericaceae). Their structures were elucidated on the basis of spectral analysis.

A tandem metal carbene cyclization-cycloaddition approach to the pseudolaric acids.

An approach toward the synthesis of the antifungal and cytotoxic pseudolaric acids based on the tandem metal carbene cyclization-cycloaddition reaction is described. Using this strategy, the advanced intermediate 3a bearing three of the four stereocenters of the target molecules has been synthesized. The substrate-controlled diastereoselectivity of the tandem carbene cyclization-cycloaddition was preferential for the undesired diastereomer, but reagent control through the use of Hashimoto's chiral rhodium catalyst Rh(2)(S-BPTV)(4) reversed the selectivity in favor of 3a.

Nitrotyrasacutuminine from Menispermum dauricum.

Nitrotyrasacutuminine, an unusual nitrated morphine-type alkaloid was isolated from the roots of Menispermum dauricum. Its structure was determined by various 2D spectra and chemical methods.