Spiro[3.5]nonenyl Meroterpenoid Lactones, Cryptolaevilactones G-L, an Ionone Derivative, and Total Synthesis of Cryptolaevilactone M from .

A CHOH-CHCl (1:1) extract (N025439) of the leaves and twigs of furnished eight new compounds, -. Based on extensive 1D and 2D NMR spectroscopic data examination, the new δ-lactone derivatives - are monoterpene-polyketide hybrids containing a unique spiro[3.5]nonenyl moiety. Their trivial names, cryptolaevilactones G-L, follow those of the related known meroterpenoids cryptolaevilactones A-F. Cryptolaevilactone L () contains 11,12--oriented substituents, while the other cryptolaevilactones contain -oriented groups. The structure of the linear δ-lactone , cryptolaevilactone M, was characterized from various spectroscopic data analysis, and the absolute configuration was determined by total synthesis through stereoselective allylation and Grubbs olefin metathesis. Compound was elucidated to be an ionone derivative with a 3,4--diol functionality.