The chemistry of thujone. XX. New enantioselective syntheses of Ambrox and epi-Ambrox

1997 ◽  
Vol 75 (8) ◽  
pp. 1136-1150 ◽  
Author(s):  
James P. Kutney ◽  
Carles Cirera
Keyword(s):  
Starting Material ◽  
Synthetic Approach ◽  
Formal Synthesis ◽  
Red Cedar ◽  
Western Red Cedar ◽  
Enantioselective Syntheses ◽  
Chiral Synthon

The development of a new synthetic approach to (−)-Ambrox® (37) and epi-Ambrox® (29) using thujone (1) as a chiral synthon, is presented. Thujone (1), a readily available starting material obtained from Western red cedar, can be efficiently converted to β-cyperone (2) and the latter is then chemically elaborated to the key intermediate, the enone 6. A carbonyl transposition of 6 to enone 9 also allows a formal synthesis of (−)-Polywood® (18). Keywords: thujone, β-cyperone, (−)-Ambrox®, epi-Ambrox®, synthesis.

Mass and nutrient content of woody debris and forest floor in western red cedar and western hemlock forests on northern Vancouver Island

1993 ◽  
Vol 23 (6) ◽  
pp. 1052-1059 ◽  
Author(s):  
Rodney J. Keenan ◽  
Cindy E. Prescott ◽  
J.P. Hamish Kimmins
Keyword(s):  
Forest Floor ◽  
Forest Type ◽  
Woody Debris ◽  
Nutrient Content ◽  
Vancouver Island ◽  
Western Hemlock ◽  
N Availability ◽  
Red Cedar ◽  
The Mean ◽  
Western Red Cedar

Biomass and C, N, P, and K contents of woody debris and the forest floor were surveyed in adjacent stands of old-growth western red cedar (Thujaplicata Donn)–western hemlock (Tsugaheterophylla (Raf.) Sarg.) (CH type), and 85-year-old, windstorm-derived, second-growth western hemlock–amabilis fir (Abiesamabilis (Dougl.) Forbes) (HA type) at three sites on northern Vancouver Island. Carbon concentrations were relatively constant across all detrital categories (mean = 556.8 mg/g); concentrations of N and P generally increased, and K generally decreased, with increasing degree of decomposition. The mean mass of woody debris was 363 Mg/ha in the CH and 226 Mg/ha in the HA type. The mean forest floor mass was 280 Mg/ha in the CH and 211 Mg/ha in the HA stands. Approximately 60% of the forest floor mass in each forest type was decaying wood. Dead woody material above and within the forest floor represented a significant store of biomass and nutrients in both forest types, containing 82% of the aboveground detrital biomass, 51–59% of the N, and 58–61% of the detrital P. Forest floors in the CH and HA types contained similar total quantities of N, suggesting that the lower N availability in CH forests is not caused by greater immobilization in detritus. The large accumulation of forest floor and woody debris in this region is attributed to slow decomposition in the cool, wet climate, high rates of detrital input following windstorms, and the large size and decay resistance of western red cedar boles.

Influence of nursery culture on western red cedar

New Forests ◽  
1994 ◽  
Vol 8 (3) ◽  
pp. 231-247 ◽  
Author(s):  
Raymund S. Folk ◽  
Steven C. Grossnickle ◽  
John E. Major ◽  
James T. Arnott
Keyword(s):  
Nursery Culture ◽  
Red Cedar ◽  
Western Red Cedar

Characterization of the complete plastome of western red cedar, Thuja plicata (Cupressaceae)

2017 ◽  
Vol 11 (1) ◽  
pp. 79-81
Author(s):  
Kole F. Adelalu ◽  
Xiao-Jian Qu ◽  
Yan-Xia Sun ◽  
Tao Deng ◽  
Hang Sun ◽  
...  
Keyword(s):  
Thuja Plicata ◽  
Red Cedar ◽  
Western Red Cedar

THE BEHAVIOUR OF FIVE WOOD SPECIES IN COMPRESSION

IAWA Journal ◽  
2002 ◽  
Vol 23 (2) ◽  
pp. 201-211 ◽  
Author(s):  
Simon Ellis ◽  
Paul Steiner
Keyword(s):  
Young’S Modulus ◽  
Populus Tremuloides ◽  
Wood Species ◽  
Young's Modulus ◽  
Douglas Fir ◽  
Thuja Plicata ◽  
Trembling Aspen ◽  
Moisture Contents ◽  
Red Cedar ◽  
Western Red Cedar

Five wood species, Oregon ash (Fraxinus latifolia Benth.), Balau (Shorea spp.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), Western red cedar (Thuja plicata Donn ex D. Don), and Trembling aspen (Populus tremuloides Michx.) were loaded in compression longitudinally, radially and tangentially. The wood cubes were conditioned to one of four moisture contents prior to loading. Small cubes were loaded until no void space remained after which samples were released and soaked in water. Stress /strain curves were recorded over the whole range of strain and cube thicknesses were recorded at the end of the compression, after release from the testing apparatus, and after soaking in water. Denser woods resulted in a greater Young’s modulus, higher levels of stress and shorter time to densification than did less dense woods. Higher initial moisture contents apparently increased the plasticity of the wood leading to a lower Young’s modulus and lower levels of stress during compression, greater springback after release of stress and greater recovery after swelling in water. Differences observed in the radial and tangential behaviours were believed to be due to the supporting action of the rays when the wood was compressed in the radial direction in balau and trembling aspen and to the relative difference between the lower density earlywood and higher density latewood regions in ash, Douglas-fir and western red cedar.

Mass Transfer Characteristics of Western Hemlock and Western Red Cedar

Holzforschung ◽  
2002 ◽  
Vol 56 (2) ◽  
pp. 185-190 ◽  
Author(s):  
Anastasios Koumoutsakos ◽  
Stavros Avramidis
Keyword(s):  
Mass Transfer ◽  
Western Hemlock ◽  
Transfer Characteristics ◽  
Red Cedar ◽  
Western Red Cedar

Thermal characterization and ignition study of Western Red Cedar exposed to firebrand attack

2021 ◽  
Author(s):  
Jacques De Beer ◽  
Joseph Alascio ◽  
Stanislav Stoliarov ◽  
Michael Gollner
Keyword(s):  
Thermal Characterization ◽  
Red Cedar ◽  
Western Red Cedar

New Method to Isolate Gamma-Thujaplicin from Western Red Cedar (Thuja plicataDonn.)

2010 ◽  
Vol 30 (3) ◽  
pp. 299-314 ◽  
Author(s):  
Zhi-Ming Liu ◽  
C. R. Daniels ◽  
Paul I. Morris
Keyword(s):  
New Method ◽  
Red Cedar ◽  
Western Red Cedar

Lignans of western red cedar (Thujaplicata Donn). IX. Plicatinaphthalene

1969 ◽  
Vol 47 (23) ◽  
pp. 4495-4498 ◽  
Author(s):  
Harold MacLean ◽  
B. F. MacDonald
Keyword(s):  
Thin Layer ◽  
Water Soluble ◽  
Hot Water ◽  
Methylenedioxy Group ◽  
Red Cedar ◽  
Naphthoic Acid ◽  
Trimethyl Ether ◽  
Acid Lactone ◽  
Western Red Cedar ◽  
Layer Chromatography

The last of nine lignans detectable by thin-layer chromatography in the hot-water soluble extractives of western red cedar (Thujaplicata Donn) heartwood has been determined as 6-hydroxy-2(hydroxy-methyl)-7-methoxy-4-(3′,4′-dihydroxy-5′-methoxyphenyl)-3-naphthoic acid lactone (plicatinaphthalene 2) by spectrometric methods, by degradation studies of derivatives, and by preparation of its trimethyl ether derivative 3 from dehydroanhydropicropodophyllin by opening of the methylenedioxy group with boron trichloride.

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