Expedient synthesis of villosin and its isomer (E)-labda-8(17),12,14-trien-15(16)-olide

The synthesis of the title compounds has been achieved in concise, highly regiocontrolled fashion from commercially available (+)-sclareolide. In addition, we offer evidence that the structure of a newly reported natural product from Zingiber ottensii is incorrect.     

Synthesis of hedychenone, yunnancoronarins and aframodial derivatives

Starting with larixol, syntheses of furan and 1,4-enedial labdane-type diterpenes are presented, which has enabled a preparation of hedychenone (20% yield).     

Semisynthesis of (+)-angeloyl-gutierrezianolic acid methyl ester diterpenoid

This paper describes the use of zamoranic acid in the first semisynthesis of the furolabdane (+)-angeloyl-gutierrezianolic acid methyl ester diterpenoid, which also establishes the absolute configuration of the natural product. Direct deconjugation of Δ⁷ in zamoranic acid and Bestmann methodology for the furan ring synthesis are the key steps.     

Nine New ent‐Labdane Diterpenoids from the Aerial Parts of Andrographis paniculata

Nine new ent‐labdane‐type diterpenoids ( 1 – 9 ), mostly in the form of the corresponding 16,15‐lactones, were isolated from the 85%‐EtOH extract of the aerial parts of Andrographis paniculata Nees. , together with nine known compounds ( 10 – 18 ). Their structures were deduced by in‐depth NMR spectroscopy and high‐resolution mass spectrometry.     

New Labdane‐Type Diterpenoids from Amentotaxus argotaenia

A new labdane diterpene, amentotaxin A ( 1 ), and an unprecedented dinorlabdane diterpene, amentotaxin B ( 2 ), were isolated from the stems of Amentotaxus argotaenia (Hance) Pilger , together with seven known compounds. Their structures were identified by in‐depth spectroscopic and mass‐spectrometric analyses.     

Synthesis of sibiricinone A, sibiricinone B and leoheterin

Two labdenolides, sibiricinone A and sibericinone B, and a furo-labdane leoheterin have been synthesized from sclareol, for the first time, establishing in this manner the absolute configuration for these compounds.     

Synthetic studies to highly functionalised B ring labdanes

Several 6,7-dioxygenated (cis or trans) labdanes have been synthesised starting from sclareol. A new strategy that allows the obtention of diols α-cis as well as β-cis or trans is described. In particular, the syntheses of three natural highly functionalised labdanes in the B rings of 2, 3 and 4 with different side chains are reported. The syntheses have permitted to correct the proposed structure for one of them.     

Diterpenoids from the Wood of Cunninghamia konishii

Investigation of the wood of Cunninghamia konishii resulted in the isolation and characterization of one new abietane diterpenoid, (6α,7β)‐7,8‐epoxy‐6‐hydroxyabieta‐9(11),13‐dien‐12‐one ( 1 ), and two new labdane diterpenoids, (12R)‐12‐hydroxylabda‐8(17),13(16),14‐trien‐19‐oic acid ( 2 ) and (12R)‐12‐hydroxylabda‐8(17),13(16),14‐trien‐18‐oic acid ( 3 ). The structures of these new compounds were elucidated by analysis of their spectroscopic data.     

Diterpenoids from Diplopterygium rufopilosum

Two new diterpenoids, (3β,13S)‐3‐O‐[6‐O‐acetyl‐β‐D ‐glucopyranosyl]‐13‐O‐α‐L ‐rhamnopyranosyllabda‐8(17),14‐diene ( 1 ) and (4R,13S)‐18‐O‐β‐D ‐glucopyranosyllabda‐8(17),14‐dien‐13‐ol ( 2 ) have been isolated from the 95% EtOH extract of the dry fronds of Diplopterygium rufopilosum. Their structures were characterized by spectroscopic methods, including 1D‐NMR, 2D‐NMR, and HR‐ESI‐MS.     

Two New Labdane‐Type Diterpene Acids from the Wood of Cunninghamia konishii

Two new labdane‐type diterpene acids, (12S)‐12‐hydroxylabda‐8(17),13(16),14‐trien‐18‐oic acid ( 1 ) and (12R)‐12‐hydroxy‐15,16‐epoxylabda‐8(17),13‐dien‐18‐oic acid ( 2 ), along with a known labdane‐type diterpene, (11E)‐15,16‐bisnor‐13‐oxolabda‐8(17),11‐dien‐19‐oic acid ( 3 ), were isolated from the MeOH extract of the wood of Cunninghamia konishii. Their structures were determined by analysis of spectroscopic data and comparison with the data of known analogs.